Windham Tech HVAC

• Solid State

• Current Coil

• Potential

Starting Relays

Windham Tech HVAC

Solid State1. Solid state material2. No contacts3. Positive Temperature Coefficient PTC4. Resistance increases from 0 to 20,000 + ohms as electrons flow material increases in temperature5. Material needs to cool before restarting6. Wide range of applications 1/8 to 1/2 HP & 1/2 to 5 Hp

Starting Relays

Windham Tech HVAC

Solid State

1. Split Phase

2.Wired in series with start windings

Starting Relays

Windham Tech HVAC

Solid State

1. CSIR

2.Wired in series with start windings and Capacitor

Starting Relays

Windham Tech HVAC

Solid State

1. CSCR

2.Wired in series with start windings and Capacitor

Starting Relays

Windham Tech HVAC

Solid State1. PSC2.Wired in parallel with Run Capacitor3. Increases starting torque4. By passes capacitor during start up

Starting Relays

Windham Tech HVAC

Current Coil Relay1. Operates on motor current2. Positional3. Often plugs on to compressor terminals4. Must match motor HP

Starting Relays

Windham Tech HVAC

Current Coil Relay1. Coil energizes when motor current is high at start up2. As current drops when motor reaches running RPM the coil de-energizes

Starting Relays

Windham Tech HVAC

Current Coil RelaySplit phase Wiring

Starting Relays

Windham Tech HVAC

Current Coil RelayCSIR Wiring

Starting Relays

Windham Tech HVAC

Current Coil RelayCSR Wiring

Starting Relays

Windham Tech HVAC

Potential Relay1. Sometimes called the Voltage Relay2. Operates on input voltage and voltage created in motor Start windings3. Terminals numbered 1,2,5

Starting Relays

Windham Tech HVAC

Potential Relay1. Must match motor HP2. As motor reaches 75% RPM voltage

created in start winding adds to input voltage to create “Pick Voltage”, coil energizes

3. When relay energizes combined voltage may lower. If voltage drops below “Drop Voltage” relay de-energizes

4. When motor is operating the combined voltage must stay above the “Hold Voltage”

Starting Relays

Windham Tech HVAC

Potential RelaySplit phase Wiring

Terminal 2 always connects to startTerminal 5 always connects to common between compressor and

overload

Starting Relays

Windham Tech HVAC

Potential RelayCSIR

Start Cap must be before relayTerminal 5 always connects to common between compressor and

overload

Starting Relays

Windham Tech HVAC

Potential RelayCSR

Start Cap must be before relayTerminal 5 always connects to common between compressor and

overload

Starting Relays