MF-12APINSPOTTER

MF-12AMF-12A

MACHINERY DIVISION

OWNER’SOWNER’SMANUALMANUAL

®

TIMER ADJUSTMENTTIMER ADJUSTMENT

The MF-12A has been designed and built to withstand rugged shop. Constant, trouble-free operation is as-sured with a minimum of maintenance. The GUN TIP, the GROUND CLAMP and all CABLE CONNECTIONSshould be kept clean to maintain a good electrical contact. Wire brush the parts to remove any oxida-tion or adhesive that may have accumulated during the fastening operation.

The timer dial facing you on the front panel of theunit, determines the duration of the weld cycle. Formaximum efficiency of the unit, the weld cycle should be set for the shortest length of time necessary toprovide a good weld. An excessive amount of time does not improve the weld. On the contrary, the resultingweld may not be an acceptable one. It is recommended that at the start of a production run, using a givenlength of pin with a given gauge of metal, the opera-tor take a few moments to determine the minimum timer setting to perform the job and leave the timer at that point.NOTE: There is a common misconception that thelonger the weld time, the stronger the weld. This isnot true. It is important that you follow the above instructions for maintaining the minimum weld time.

MAINTENANCEMAINTENANCE

ELECTRICAL REQUIREMENTSELECTRICAL REQUIREMENTS

Where duct is too large to put on a bench, snap the ground clamp onto the duct and secure the insula-tion quickly by welding the Clip Pins inside or outside of the ducts as required. Eliminate the heat mark on the duct using the simple “heat sink” supplied on the opposite side of the weld.

BRING MF-12A TO THE WORKBRING MF-12A TO THE WORK

MF-12A AS A BENCH TOOLMF-12A AS A BENCH TOOL

Connect the MF-12A to a 60 amp power supply. (208-230 volts – 60 cycle). The MF-12A uses 208 – 230 volt single phase. To wire to 208-230 volt single phase, the green lead is ground and the white and black leads are power. It is suggested that the unit be permanently wired into a 60 amp disconnect box fitted with 60 amp circuit protection.

To use your work bench as a welding table, set theMF-12A alongside or on top of the work bench. Coverthe bench top with a copper sheet (.025 inch) which will act as a permanent ground when the duct workis placed on the table top. Attach the MF-12A ground clamp to the duct work or copper bench top. The Clip Pins will quickly weld every time with no burn marksor wasted pins due to misfires.

INSTALLING CLIP PINSINSTALLING CLIP PINSClip Pins are welded as easily as "A", "B", "C".

"A""A"

Press down through the insu-lation, twist the gun, and pull the trigger. Do not release the trigger until the timer cycle has ended.

"B""B"

Position the Clip pin on the Magnetic tip of hand gun.

The Clip Pins are permanently welded in position flush with the insulation.

"C""C"

SERVICE SERVICE The MF-12A has been designed and built to withstand rugged shop usage. The Indicator lights on the front panel will help you to diagnose minor problems. If your MF-12A fails to operate follow this simple procedure to find the defective component.

1. Pull the trigger and watch the lights. The green light (24 volts) and then the red light (220 volts) should flash on and off.

2. If only the green light comes on, go to step 4.

3. If neither light comes on, press the WELD CYCLE TEST switch on the front panel. A. If both lights flash and the transformers do not

hum go to step 5.B. If both lights flash and the transformers hum,

the problem is either a bad trigger switch or bad switch cable.

C. If only the green light flashes, go to step 4D. If neither light flashes, replace 24 volt trans-

former.

4. Replace the weld activator.

5. The problem is probably a bad weld transformer. Call technical service for further assistance.

(1-800-899-3876)

MF-

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RA

MM

F-12A W

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G D

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MF-

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TEST

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24V

TRAN

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POW

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LIG

HT

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220V

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TPU

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BLK

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(20Ga)

IND

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ITC

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N/Y

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24V

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GU

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ABLE

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BUSS

BAR

WH

T

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DTI

ME

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1/L1

4/A2

3

2/T1

1

3/A1

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24

TIM

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ST: 2

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(16G

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(20G

a)

(20G

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0Ga)

(20G

a)(1

6Ga)

(16G

a)

(20G

a)

(10Ga)

(16G

a)

(16G

a)

(16G

a)

(16Ga)

(16G

a)(1

2Ga)

(12Ga)

(12Ga)

(12Ga)(12Ga)

(12G

a)

(12Ga)

12

34

5G

G6

78

910

1112

198V

220V

242V

264V

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WHT

PARTS

LO

CAT

ION

PARTS

LO

CAT

ION

27316 R

ed

Sta

tus

Ligh

t17309 P

ower

Sw

itch

17320 W

eld

Pot

enti

omet

er27326 K

nob

17308 U

nive

rsal

A

mbe

r L

ight

27315 G

reen

S

tatu

s Li

ght

39110 T

est

Sw

itch

17079 R

ubbe

r Fo

ot

27098 C

ase

Bod

y

27213 F

emal

e Fl

ush

Mou

nt C

amlo

ck

17327 S

wit

ch C

able

Rec

epta

cle

27097 O

val

Gri

p H

andl

e

27094 2

20 V

olt

Tran

sfor

mer

17310 2

4 V

olt

Tran

sfor

mer

17140 W

eld

Act

ivat

or

27354 2

0-6

Pus

h-in

Te

rm G

rnd

Boc

k

27351 P

ush-

In

Term

Blo

ck E

nd P

late

27353 2

2-1

2

Pus

h-in

Te

rmin

al B

lock

27352 2

0-6

Pus

h-in

Ter

m

Blo

ck

27354 T

erm

inal

B

lock

Jum

per

27355 2

2-1

2

Pus

h-in

Ter

m

Grn

d B

lock

PARTS

LO

CAT

ION

PARTS

LO

CAT

ION

27100 S

crew

s (6

)

27

10

3 G

un B

ody

(Rt

& L

ft H

alve

s)

27

10

2 S

pind

le S

haft

27

10

3 G

un B

ody

(Rt

& L

ft H

alve

s)

27

10

1 T

aper

Ada

pter

27104 F

ace

Pla

te N

ut

270

99

Tri

gger

Sw

itch

(N

o Le

ads)

MF-12A PARTS & SPECIFICATIONSMF-12A PARTS & SPECIFICATIONS

17049 Male Camlock17079 Rubber Foot17140 Weld Activator17288 Switch Cable Plug17308 Universal Amber Light17309 Power Switch17320 Weld Potentiometer17327 Switch Cable Receptacle27005 TP-2 Tip27091 Gun or Ground Cable only - 10ft27092 Gun Switch Assembly - 11ft27093 Cable & Electrode Assembly - 10ft27094 220 Volt Transformer27095 Ground Clamp Assembly - 10ft27096 Gun Cable Assembly - 10ft27097 Oval Grip Handle27098 MF12-A Case Body27099 Trigger Switch - No Leads27100 Thread Form Screw - 6pk27101 Tapered Adapter27102 Spindle Shaft27103 Gun Body (Rt & Left)27104 Face Plate Nut27213 Female Flush Mount Camlock27217 Line Cord27230 TP-9 Tip

27231 Electrode Assembly27236 Fibre Sleeve27237 Electrode27238 Roll Pin27240 Case Screws27244 Brass Jack27245 Gun Switch27246 Gun Case27253 Line Cord - Strain relief27315 Green Status Light27316 Red Status Light27318 Case Top Cover with Handle 27320 Case Side Panel27322 Top Handle27326 Weld Potentiometer Knob27343 Socket Cover27351 Push-In Term Block End Plate27352 20-6 Push-in Term Block27353 22-12 Push-in Terminal Block27354 MF12A Terminal Block Jumper27355 22-12 Push-in Term Grnd Block27356 20-6 Push-in Term Grnd Block39110 Test Switch44091 24V Multi-Tap Transformer

ITEM DESCRIPTION ITEM DESCRIPTION

NOTES

Duro Dyne Corporate Headquarters, Bay Shore, NY631-249-9000 • Fax: 631-249-8346

Duro Dyne Midwest • Duro Dyne West • Duro Dyne Canadawww.durodyne.com • E-mail: durodyne@durodyne.com

Please Visit Our Website

www.durodyne.comfor the most up to date product information.

®

MACHINERY DIVISION© 2021 Duro Dyne CorporationPrinted in USA 6/2/2021