technical bulletin wdp-tb-r0 whisper-drive

All Bebco Model WDP Wall Mount Dual Blower Whisper-Drive™ NFPA 496 Building Pressurization Units are Classified by Underwriters Laboratories Incorporated to meet or exceed all requirements of NFPA 496 for safely pressurizing a building, room or sealed structure in a hazardous (classified) location.

DIVISION 1 AREA APPLICATION NOTEINSTALLER MUST PROVIDE DISCONNECT EQUIPMENT TO AUTOMATICALLY REMOVE POWER FROM ALL NONRATED DEVICES WITHIN THE PROTECTED ROOM OR BUILDING,

UPON FAILURE OF THE PRESSURIZATION UNIT.

Product IntroductionBebco Model WDP Wall Mount Whisper-Drive™ NFPA 496 Building Pressurization Units are the world’s finest stand-alone building pressurizers! These self contained units are intended for control rooms or buildings that may or may not contain an internal source of flammable vapors or gases, since they can also operate as emergency ventilation units! Four different sizes are suitable for rooms or buildings with opening(s) ranging up to 75 square feet and floor areas up to 12,000 square feet, but they can work in tandem for larger spaces. They also work well with HVAC units, by automatically minimizing the air necessary to accomplish effective pressurization.

In addition, their fully seal-welded housings, coupled with a variable speed drive and extremely flexible control options, allow these units to pressurize buildings and rooms easily while maintaining the lowest possible noise levels, often well below 70 decibels!

To ensure ultra-quiet operation, these units feature primary and secondary axial fans to pressurize rooms or buildings. The primary fan is controlled by a variable speed drive to quietly maintain a safe (0.25 ”) pressure when all openings (typically doorways) are sealed. The secondary fan is controlled by an optional delay timer, which engages the fan only upon loss of safe pressure when doorways are opened, to generate a minimum air velocity of sixty (60) feet per minute through the open doorways. As an added safety benefit, the secondary fan also functions as a redundant fan to maintain building pressure, if the primary fan fails.

When combined with an intake stack drawing fresh air from an unclassified area, these units reduce the hazardous (classified) area rating within your room or building, as UL Classified, from Class I, Division 1 or 2 Groups C and D, to unclassified, in accordance with NFPA 496.

After basic calibration is performed to set a preferred room pressure, an alarm set point and preferred time delays for pressure loss alarm and secondary fan activation, Unit operation is very easy and status indicators keep occupants informed of unit performance at all times. The unit is started by closing all doors, placing the secondary fan switch in the “automatic” position and placing the primary fan switch in the “on” position. The primary fan then engages to regulate air flow and maintain a safe pressure. When a door is opened, the primary fan will increase velocity, in an attempt to hold pressure in the room or building, and the unit will activate the pressure loss alarm and secondary fan activation delay timers if pressure falls below the alarm set point. As the door is closed, and room or building pressure rises above the alarm set point, the secondary fan disengages, the alarm is deactivated and the primary fan throttles back automatically.

In essence, once a Bebco Whisper-Drive™ Unit is running, it maintains building pressure or velocities through an open doorway automatically, keeping you in complete accordance with NFPA 496 at all times. You then have the abilities to override the alarm, (which causes that indicator to flash as a reminder) and manually activate the secondary fan as needed to enable tasks such as moving equipment in or out of the room or building safely without annoying alarms!

Unit Certification Basic Operation

Model WDPWall Mount Dual Blower

Building Pressurization UnitsTechnical Bulletin WDP-TB-R0 © 05.1.2019

Front Views(shown without mounting bezels)

Unit must be powered by a local disconnect switch connected ahead of building power or connected to a separate power source. The unit is started by closing the building door, placing the secondary fan switch in the “automatic” position and placing the primary fan switch in the “on” position. The primary fan then engages to regulate air flow and maintain a safe pressure.

When the door is opened, pressure will fall below the alarm set point. The primary fan will then increase velocity, and the unit will activate an alarm signal delay timer and a secondary fan delay timer. Both timers are field adjustable, to permit immediate or delayed response to changes in pressure. Both timers are activated and reset as pressure falls below and rises above the alarm set point. If the secondary fan or alarm engages, they disengage when the door is sealed and pressure rises above the alarm set point.

Model WDP-24 Model WDP-20 Model WDP-16 Model WDP-12

Whisper-Drive

Variable Speed TechnologyVariable Speed Technology

This Fiberglass Analyzer Building is situated in an H2S environment of a sour gas plant, and is equipped with a Bebco Model IX-WDP Wall Mount Whisper-DriveTM

Building Pressurization Unit, featuring a urethane coated 316 stainless steel housing. It operates in tandem with a Bebco Industrial Grade 316 Stainless Steel seal-welded IX-WAC Wall Mount Air Conditioner to protect the building against both a combustible and highly corrosive environment, and applies only enough air to maintain pressurization to minimize air conditioner loads, until the door is opened. The Model IX-WDP then ramps up automatically to operate at full velocity and keep the external atmosphere at bay! In this ideal application, both the Bebco Pressurization Unit and Air Conditioner will perform just as well as the fiberglass building in this extremely harsh environment to provide years of trouble-free service!

Product ApplicationsBebco Model WDP Wall Mount Whisper Drive™ Pressurization Units are intended for industrial applications and ideal for control rooms, guard stations, motor control centers, switchgear buildings, analyzer houses, laboratories and other industrial facility structures ranging from small to large buildings with one or more rooms, due largely to their vastly superior design. Since Bebco Whisper Drive™ Units can be mounted quickly and easily through a wall cutout, or mounted to an exterior wall or on a roof and ducted into a room, or building or the fresh air intake of a packaged or wall mount HVAC unit, they are also extremely practical retrofit units.

All Bebco Model WDP Whisper-DriveTM Units are equipped with our unique Variable Speed Drive Interface (VFDI) Logic Control Boards. These boards provide a wide array of optional control features, including an emergency shutdown if combustible gas is detected in the intake stack and an emergency control override which engages the primary and secondary fans at full speed to provide high velocity ventilation if combustible or asphyxiating gases are detected within a room or building. These unique features make Bebco Model WDP Units ideal for analyzer or laboratory rooms and buildings that feature normally sealed sample analysis systems or fume hoods, and for any other buildings where critical personnel and equipment protection is essential. Redundancy is attained by the automatic activation of the secondary fan if the primary fan should ever fail, so a single Bebco unit can accomplish multiple purposes!

Best of all, a large gauge allows easy monitoring of our Whisper Drive™ Units, and Operators will also be alerted promptly to act upon failure of the pressurization unit with both an on-board indicator and alarm outputs that are available with conventional or intrinsically safe outputs.

Additionally, these units can provide a superior solution to applications in highly corrosive on-shore and off-shore locations by selecting 304 or 316 stainless steel corrosion-resistant seal-welded housings!

Consider Bebco Whisper-Drive™ Units as the World’s most

advanced and versatile building and room pressurizers, unequaled

in many dynamic ways to any other available product.

You’ll surely agree we’ve set a rugged and innovative

standard for building and room pressurization, that easily satisfies

the challenging requirements of your harsh, industrial

and corrosive environment applications!

Whisper-Drive

Variable Speed TechnologyVariable Speed Technology

In an extremely unique application, this Emergency Deluge Fire Pump Engine Building is equipped with an oversized Bebco Model WDP Wall Mount Whisper-DriveTM Building Pressurization Unit. As shown, the Unit is fed by a free-standing Bebco Model RPSK Rigid Pipe Stack, constructed from Schedule 80 carbon steel pipe and mounted to an entryway platform, next to the front door. The WDP Unit pressurizes the building and also provides emergency ventilation if interior gas detection units sense engine fuel or exhaust gases within the building. In this instance, the unique design of Bebco Pressurization Units meets the challenge easily, with no custom modifications!

of 10 BECC-WDP-TB-R1 Bebco Environmental Controls Corporation - Copyright © 2019

Case Style ICThis case style is intended for passive chemical processing and refining facilities and onshore environments.

The housing, rear door, interior petitions, and motor mounting bracket of all Model WDP Units are constructed from 14 gauge urethane coated galvannealed steel, while all fan venturi rings and intake stack port cover plates, along with the control enclosure cover, interior trim bezel and exterior angle flange brackets of Model WDP Units are constructed from 18 gauge urethane coated galvannealed steel.

To enhance overall corrosion resistance or match the finish or color scheme of a building, IC style housings can be provided with a custom finish, using any brand, color and application method you prefer including powder coated finishes, specified by you at time of order!

Case Styles & Materials

Case Styles IS & IXThese case styles are intended for mild to highly corrosive chemical processing and refining facilities, coastal and offshore environments.

The housing, rear door, interior petitions, and motor mounting bracket of all Model WDP Units are constructed from 14 gauge urethane coated 304 or 316 grade stainless steel, while all fan venturi rings and intake stack port cover plates, along with the control enclosure cover, interior trim bezel and exterior angle flange brackets of Model WDP Units are constructed from 18 gauge urethane coated 304 or 316 grade stainless steel.

To enhance overall corrosion resistance or match the finish or color scheme of a building, IS and IX style housings can be provided with a custom finish using any brand, color and application method you prefer including powder coated finishes, as specified by you at time of order!

Seal-Welding Provides a Significant Advantage!

Among the many and vastly superior features of Bebco Whisper-DriveTM Building Pressurization Units,

our seal-welded cases ensure amazingly quiet operation for years of annoyance-free service!

Copyright © 2019 - Bebco Environmental Controls Corporation BECC-WDP-TB-R1 of 10


Standard FeaturesUnit Control FeaturesField Adjustable Set Points & Delay TimersProvides room pressure and alarm pressure settings, along with secondary fan and alarm activation timers.

Room Pressure & Alarm Activation Set Points

• PFS: Primary Fan Speed Set Point Adjustment sets primary fan speed to maintain safe room pressure Factory Set Point: 0.25” w.c./ Range: 0.05” w.c. to 0.25” w.c.• ASP: Alarm Activation Set Point Adjustment sets alarm to activate upon loss of safe room pressure

Factory Set Point: 0.15” w.c. / Range: 0.05” w.c. to 0.25” w.c.

Secondary Fan & Alarm Activation Delay Timers

• SFD: Secondary Fan Activation Delay Adjustment sets time delay cycle to prohibit the secondary fan from engaging when room pressure falls below alarm set point.

Factory Set Point: 0 seconds / Range: 0 to 35 seconds• ASD: Alarm Signal Activation Delay Set Point sets time delay cycle to prohibit alarm signal output when room pressure falls below alarm set point.

Factory Set Point: 0 seconds / Range: 0 to 35 seconds

Delay Timers reset automatically if Safe Pressure is restored prior to expiration of the delay timer cycles.

All Bebco Whisper-Drive™ Wall Mount Building Pressurization Units feature a unique set of controls that ensure absolute compliance with all NFPA 496 Code requirements; while operating in a manner you prefer to establish critical parameters and preferred delays that ease entry and exit of your room or building and prevent unnecessary alarms.

These controls are located on the Variable Frequency Drive Interface (VFDI) Logic Control Board, as two set point adjustments and two delay timer adjustments. Adjustments take affect in real time, as on-board micro-processor inputs, that are redundantly monitored by a watchdog timer and pulsing led, to supervise performance and display real-time operating status.

System Control FeaturesField Adjustable Set Points & Delay TimersProvides room pressure and alarm pressure settings, along with secondary fan and alarm activation timers.

• Room Pressure 4” Color Coded Differential Pressure Gauge Indicator: indicates room pressure at range of 20 feet

• Primary Fan Green Indicator Light On Indicator: illuminates when primary fan is engaged

• Primary Fan On/Off Selector Switch Control Switch: engages and disengages primary fan

• Secondary Fan Off/Manual/Automatic Selector Switch Control Switch: disengages, manually engages or automatically engages secondary fan

• Alarm Engaged: Red Indicator Light illuminates when alarm signal is active flashes when alarm is disabled

• Alarm Signal On/Off Selector Switch Bypass Switch: enables or disables alarm signal

All Bebco Model WDP Whisper-Drive™ Building Pressurization Units feature necessary indicators and controls to maintain room or building pressurization or outward velocities through openings automatically upon loss of pressure. Operation is easy, beginning with startup. Once doors are sealed and the secondary fan control switch is placed in its automatic mode, the unit is started by engaging the primary fan control switch. The green primary fan engaged indicator will then illuminate to indicate the unit is running, as it establishes a safe pressure within the room automatically. From that point forward, the unit maintains NFPA 496 Code compliance with no need for further adjustments! If pressure is lost, the secondary fan will engage and the alarm signal will be activated immediately or as permitted by settings of their separate corresponding delay timers and the red alarm engaged indicator will illuminate to confirm loss of pressure.

When doors must be left open for a prolonged period of time, the secondary fan control switch may be placed in its manual mode and the alarm signal bypass switch may be used to disable the alarm signal, which in turn will be indicated by flashing of the red alarm engaged indicator. In essence, you’ll find our pressurization units extremely easy to operate, but for more information on how to utilize these controls to your benefit, please contact a Bebco Sales Associate!

Our large4” diameter

Room PressureGauge can be

read easilyfrom up to10-15 feet

away!

Room Pressure Indicator

Primary Fan On Indicator

Primary Fan Control Switch

Secondary Fan Control Switch

Alarm Engaged Indicator Alarm Signal Bypass Switch

Junction Box Electrical Wiring Diagram

1234

GroundL1 (hot)L2 (hot)ALARM (NO)

56

ALARM (C)ALARM (NC)(Not Used)(Not Used)

78

UNIT POWER208

240v 1 60Hz

ALARM RELAY15A@120VAC

AC POWER & ALARMJUNCTION BOX

OPTIONALESD & ECO INPUT JUNCTION BOX

(HARDWIRE VERSION)

ESDCONTROL

ECOCONTROL

OPTIONALESD & ECO INPUT JUNCTION BOX

(INTRINSICALLY SAFE VERSION)

REMOTE ESDCLOSED CIRCUIT

REMOTE ECOCLOSED CIRCUIT

ESDCONTROL

ECOCONTROL

REMOTE ESDCLOSED CIRCUIT

REMOTE ECOCLOSED CIRCUIT

1234

1234

O/

Programmable FeaturesFIELD-ADJUSTABLE

PRESSURE & ALARM SETPOINTS

PFS - (Primary Fan Speed) Adjusts primary fan speed toset “safe” room pressure.

Factory setpoint: 0.25” Adjustment range: 0.10” to 0.40”

ASP - (Alarm Setpoint) Adjusts alarm setpoint to activatealarm upon loss of “safe” pressure.

Factory setpoint: 0.15” Adjustment range: 0.05” to 0.25”

FIELD-ADJUSTABLESECONDARY FAN & ALARM DELAY TIMERS

SFD - (Secondary Fan Delay) Adjusts time delay cycle to prohibit secondary fan from engaging when room pressure falls below alarm setpoint.

Factory setpoint: 0 seconds Adjustment range: 0-35 seconds

ASD - (Alarm Signal Delay) Adjusts time delay cycle toprohibit alarm relay from deenergizing when room pressure falls below alarm setpoint.

Factory setpoint: 15 seconds Normal range of adjustment: 0-35 seconds

Delay Timers reset automatically if Safe Building Pressure is restored before time out.

OPTIONAL USER INPUTS

ESD - (Emergency Shutdown) Remotely disengages Primary and Secondary Fans, regardless of Primary and Secondary Fan Control Switch positions.

Typical input devices: emergency shutdown switches, fire alarm systems and stack mounted combustible gas or hydrogen sulfide sensors.

ECO - (Emergency Control Override) Remotely engages Primary and Secondary Fans, regardless of Primary and Secondary Fan Control Switch positions.

Typical input devices: room mounted combustible gas, hydrogen sulfide, or oxygen deficiency sensors.

OPTIONAL WIRING METHODS

HW - (Hard Wiring) Selection of this option requires theuse of conduit, seals and wiring approved for the location.

IS - (Intrinsically Safe) Selection of this option allows useof intrinsically safe cabling approved for the location.

NOTE: Loops are self-powered 5 VDC 20 ma signals, regardless of wiring method selection. Signals must be maintained independently by normally closed switches to prevent shutdown or override.

PRIORITY SELECTION SWITCH

In cases where both optional inputs are utilized, VFDInterface Board jumper allows user to select the preferred action (shutdown or override) in the unlikely event of simultaneous loss of signal. When VFD Interface Board priority (PTY) jumper is installed, priority is given to the Emergency Control Override function.

See rear cover for ESD & ECO input ordering information.

Emergency Controls

VariableFrequency Drive

VFD Interface Card

Control Operators & Indicators

Operator WiringCable Interface Card

VFDInterface

Cable Header

Alarm Signal Delay Timer

(ASD)

Primary Fan Speed Control

(PFS)

Alarm Setpoint Control(ASP)

Secondary Fan Delay Timer

(SFD)

Transformer

1 Amp L1Input Fuse

220 VAC PowerIn (Gnd, L1, L2)

Secondary MotorOutput (T1 & T2)

Transducer Interface

Cable Header

ESD & ECO Interface

Cable Header

Microprocessor

Door CardInterface

Cable Header

ECO Enable Pin

ESD Enable PinPriority Select Pin

Alarm Relay

20 Amp T1 & T2Output Fuses

Sec. Fan Relay

Alarm RelayTerminals

Explosion ProofControl Enclosure

Explosion ProofControl Enclosure Door

VFD Interface Card


Control Enclosure & VFD Card Features

Common Unit SpecificationsOperating Temp Range -40° F - 120° FPower Requirements: 208 / 240 VAC 1Ø, 20 ASafe Pressure Set Point: 0.15” - field adjustableAlarm Set Point: 0.15” - field adjustableNormal Sound Level: ** 60 db min. / 70 db max.Conduit Entries: 3/4” FPTAlarm Contact Rating: 15 Amps @ 120 VACDiv. 1 Motor Rating: Cl. I, Div. 1, Gr. C & DDiv. 2 Motors Rating: Cl. I, Div. 2, Gr. C & DPrimary Motor: 3Ø Inverter Duty, T3, 100 HzSecondary Motor: 1Ø Perm. Split Cap., T3, 60 Hz

WDP-12 Unit Specifications

Shipping Dimensions: 48” h x 24” w x 34” dShipping Weight: 340 lbs.Average CFM: * 65.24 feet/min.Maximum CFM: 1370 feet/min.Normal Sound Level: ** 60 db min. / 70 db max.Fresh Air Intake: 12” DiameterPrimary Motor RPM: 3000 Max.Secondary Motor RPM: 1725 Max.

WDP-16 Unit SpecificationsShipping Dimensions: 59” h x 32” w x 41” dShipping Weight: 480 lbs.Average CFM: * 73.98 feet/min.Maximum CFM: 4069 feet/min.Normal Sound Level: ** 60 db min. / 70 db max.Fresh Air Intake: 20” DiameterPrimary Motor RPM: 1725 Max.Secondary Motor RPM: 1725 Max.



* Average CFM measured in well-sealed room. ** Normal sound level in acoustic sound chamber with primary fan engaged and doors sealed

WDP-12 Front Viewwith exhaust grill open and

control enclosure cover plate removed

WDP-12 Rear Viewwith access door

removed

HousingMounting

Bezel

BlowerHousing

Body

BuildingPressureIndicator

FlameArrestorFitting

SecondaryFan

Blade

ExhaustGrill

Frame

Full HingeExhaust

Grill

ExplosionProof

Controls

PrimaryMotor

Indicator

PrimaryMotorSwitch

SecondaryMotorSwitch

AlarmBypass

Indicator

AlarmBypassSwitch

RemovableDoorHinge

DoorFrameGasket

BlowerHousing

Body

EmergencyControlWiring

EmergencyRemote Control

JunctionBox

Emergency Control Wiring Conduit Inlet

PrimaryFan

Wiring

PrimaryFan

Motor

SecondaryFan

Motor

SecondaryFan

Wiring

AC Power& AlarmJunction

Box

AC Power& Alarm WiringConduit Inlet

Housing Feature & Component Call-Outs


Typical Installation

B

A

Primary FanEngaged

Primary FanOFF ON

Pressure LossAlarm Engaged

Alarm SystemBypass

OFF ON

Secondary FanOFF AUTO ON

SAFE

BUILDING

CAUTION

0LOW

PRESSURE

.5

INCHES OF WATER

.1.2 .3

.4

FRONT REAR

Housing Dimensions UNIT A B C D E F G H I J K L

12 16.125 37.25 29.25 28 8 12.25 28 8 37.25 12.25 28 20 16 20.19 41.25 31.16 32 10.094 16.25 32 10.094 41.25 16.25 32 21.91 20 24.19 48.25 36.25 35 12 20.25 35 12 48.25 20.25 35 23 24 28.19 56.25 42.16 39 14 24.25 39 14 56.25 24.25 39 25

All Dimensions shown in inches. All Dimensions are shownfor reference purposes only and subject to change without notice.

Housing Dimensions Chart Front & Rear Views

C12x20.7C12x20.7

3070DOOR

Custom Length SpiralSectionStack Leveling Slab(anchor bolt kit required)

Building Foundation

Spiral Stack Cap

Flange Connection(flange gasket & bolt kit required)

Spiral Pipe Section

Height as required toattain a source of freshair, containing no morethan trace amounts ofignitable gases or vapors.

Pressurized BuildingPressurization UnitSpiral Pipe Tee

Pressure IndicatorInterior Wall

Side & Top Views

I

ED

C

L

K

GH

O J

CL

1/4-20 Thread(TYP 8)

90 max.o

1/4-20 Thread(TYP 8)

I

O FI

RIGHT SIDE LEFT SIDETOP

Bebco recommends a wall cutout clearance of 0.25 inches on all sides, tofacilitate easy installation of your Whisper-DriveTM Building Pressurization Unit.

The One-Piece Front Bezel and Four Rear Trim Angle Brackets allow insertion through walls up to 8” thick, and require modest calking to seal the exterior flanges to the unit and wall surface.


Model WDP-16 Unit Accessories

GAS DETECTOR SYSTEMSCGDM-100 Combustible Gas MonitorCGDS-100 Combustible Gas SensorHGDM-100 Hydrogen Sulfide MonitorHGDS-100 Hydrogen Sulfide SensorOGDM-100 Oxygen Deficiency MonitorOGDS-100 Oxygen Deficiency SensorGDPS-100 24 VDC Monitor Power SupplyGDSB-1216 Sensor Stack Mount Bracket

WARNING NAMEPLATESBPCN-1 Building Pressurization CautionSDWN-1 Sealed Door Warning

EMERGENCY REMOTE CONTROL INPUTSESD/ECO-HW-16 Hard Wire ESD & ECOESD/ECO-IS-16 Intrin. Safe ESD & ECOESD-IS-16 Intrin. Safe ESDECO-IS-16 Intrin. Safe ECO

REMOTE ALARM BEACONS AND HORNSRAB-1 Div. 1 Remote Alarm BeaconRAB-2 Div. 2 Remote Alarm BeaconRAH Div. 1 Remote Alarm Horn

GALVANIZED OR STAINLESS STEEL SPIRAL PIPESP-16-120 10’ Flanged Stack SectionSC-16 Flanged & Screened Rain CapST-16 Flanged Tee w/ CouplerSN-16 Flanged Elbow w/ CouplerBC-16 Blind Flange Cover PlateGK-16 Flange Gasket & Bolt Kit

SPIRAL PIPE STACK & GUY WIRE ANCHOR KITS SPAK-16 Spiral Pipe Anchor Bolt KitEAGK-40-1216 Earth Anchor Guy Wire KitCAGK-40-1216 Concrete Anchor Guy Wire Kit

GAL. OR S.S. FREE STANDING RIGID PIPE STACKSRP-16-25 25’ Rigid Pipe StackRPAK-16 Rigid Pipe Anchor Bolt Kit

ADDITIONAL ITEMSFDK-16-300 25’ Flexible Duct Intake KitAUSK-5 Adjustable Unit Support KitEDS-240-20-2 2 Pole 20 Amp Disconnect

INSTALLATION & OPERATION MANUALWDP-16-IOM Inst. & Operation Manual

Model WDP-12 Unit Accessories











Model WDP-24 Unit AccessoriesModel WDP-20 Unit Accessories




















of 10 BECC-WDP-TB-R1 Copyright © 2019 - Bebco Environmental Controls Corporation - All Rights Reserved

IMPORTANT NOTES

Al l spec i f ica t ions sub jec t to change wi thout not ice .Warranty & L iab i l i ty po l ic ies ava i lab le upon request .

The simplified installation diagrams above are shown without guy wire or structural support systems, for the purpose of maintaining diagram clarity.Installers must recognize the need for adequate stack guy wire or structural

support systems as well as foundation anchoring systems. Installers assume all liability for the installation and integrity of said systems, wherein design

considerations should ensure that stack guy wire or structural support systems are capable of withstanding local inclement weather conditions.

IC Blower Housing: 14 Gauge Galvanized SteelIS & IX Blower Housing: 14 Gauge 304 or 316 Grade Stainless SteelFan Venturis: Painted Carbon SteelFan Blades: Non-Sparking AluminumPressure Gauge: Cast Aluminum w / Enamel FinishTube Fittings: 316 Stainless Steel & NylonPress. Reference Tubing: 1/4” Heavy Wall TygonUnit & Device Nameplates: Reverse Marked Lexan®

w/ 3M VSBTM AdhesiveFastener Hardware: Stainless Steel Screws & BoltsRear Door Fasteners: Cast Zinc Body / Zinc BoltElect. Enclosure & Fittings: Cast Zinc & AluminumElectrical Wiring: Brass MI Cable & Fittings w/ PVC JacketHousing Finishes: 2-4 mil Thickness MinimumLexan® and VSBTM a registered trademark of the General Electric Corporation

The body of a Model WDP is a seal welded blower housing that features one (1) full size rear access door, three (3) intake stack openings, two (2) stack opening covers, one (1) removable wall mounting bezel, four (4) mounting angle brackets, one (1) exhaust grill and one (1) reusable aluminum screen filter. The housing is suitable for self-supported mounting through walls up to 8” thick, and it can be inserted from the inside or outside.

The blower housing is fitted with primary and secondary fans, mounted in a compact, vertical arrangement, to reduce consumption of horizontal wall space. The primary fan occupies the top position, to minimize control room noise levels during normal operation. The secondary fan occupies the bottom position, just behind the exhaust grill.

The housing features a sealed cavity above the exhaust grill which contains an explosion proof control enclosure.

The enclosure contains a variable speed drive, a VFD interface card, and an array of control switches and indicators. The housing is fitted with a screw fastened cover plate that conceals the cavity and explosion proof control enclosure. Above the cover plate, the housing is fitted with a 4” building pressure indicator which is scaled to inches of water and color coded to indicate low, high and safe building pressures. The housing features a power and alarm junction box and an optional emergency remote control junction box for wiring. All devices are connected with approved fittings and MI (mineral insulated) cable.

Model Number DesignationsIC - WDP - 16 - D1 - A - T

1 - Case Style & MaterialIC - Seal-Welded Galvanneal Steel IS - Seal-Welded 304 Stainless Steel IX - Seal-Welded 316 Stainless Steel 2 - ConfigurationWDP - Wall Mount Dual Blower Building Pressurization Unit3 - Fan Blade Size12 - 12” Diameter Fan Blades16 - 16” Diameter Fan Blades20 - 20” Diameter Fan Blades24 - 24” Diameter Fan Blades4 - Area RatingD1 - Class I, Division 1, Groups C & DD2 - Class I, Division 2, Groups C & D5 - Remote Control InputsA - Hard Wired ESD & ECO InputsB - Intrinsically Safe ESD & ECO InputsC - Intrinsically Safe ESD InputD - Intrinsically Safe ECO InputX - Excluded

6 - Housing FinishG - ANSI 61 Gray Sprayed Urethane S - White Sprayed Urethane T - ANSI 61 Gray Epoxy Powder CoatedP - White Epoxy Powder CoatedU - Custom Finish

ONE (1) MODEL BPCN-1 NAMEPLATE, ONE (1) INSTALLATION & OPERATION MANUAL,

ONE (1) SEAL-WELDED FRONT MOUNTING BEZEL,FOUR (4) REAR MOUNTING ANGLE BRACKETSONE (1) LOT OF BEZEL & BRACKET SCREWS & TWO (2) BLANK OFF AIR-INLET COVER PLATES

PROVIDED WITH UNIT

MODEL NUMBER SELECTION NOTES

1: Bebco Whisper Drive™ Units require a 240 VAC Single Phase 60 Hertz 20 Amp Power Sources. Please contact us for other options.

2: Custom Ratings for Group B, Class II or Class III Areas are available. Please contact a Bebco Sales Associate regarding these options.

3: Hard Wired Inputs are lug terminals in junction box mounted within WDP Housings or in RDP Remote Control Station Enclosures.

4: Please specify custom housing finish in writing at time of order.

Material Specifications

Mechanical Description

Unit Selection ParametersWhen selecting a Bebco Model WDP Whisper-Drive™ Dual Blower Building Pressurization Unit, it is imperative to consider two parameters. Foremost, the square footage of all openings used for ingress and egress must be considered, and if so equipped, buildings with doors normally used only for the infrequent movement of equipment in and out of the building must be properly labeled and identified as doors that will normally remain sealed, so they can be excluded from the calculation required to achieve a 60 feet per minute air velocity through what NFPA 496 defines as “all openings capable of being opened”.

Model WDP Units have incrementally greater maximum air flow velocities, to satisfy required airflow through the following areas in square feet:

Model WDP-12: 21 Square Feet, Equivalent to One (1) 3’ x 7’ DoorwayModel WDP-16: 32 Square Feet, Equivalent to One (1) 4’ x 7’ DoorwayModel WDP-20: 55 Square Feet, Equivalent to One (1) 6’ x 8’ DoorwayModel WDP-24: 75 Square Feet, Equivalent to Three (3) 3’ x 7’ DoorwaysIn addition, the second consideration is integrity of the room or building to be sealed. If tightly sealed in all manners, with no significant leakage, and elements such as conduit penetrations being fully sealed, a unit sized strictly on the basis of the total square footage of doorway openings will likely suffice. However, if the building is suspected to have abnormally high leakage, a larger system may be warranted.

Please note we will be pleased to assist you in every way with selecting the proper Model WDP Unit. Simply contact us at your convenience for help!

technical bulletin wdp-tb-r0 whisper-drive

Documents