Installation Instructions
General Purpose Switching Relays
Supco series 903 relays are double pole, double throw (DPDT) devices primarily
used for various applications in heating, air conditioning and refrigeration. They
are also suitable for general purpose switching applications in appliance vending
machines, fan controls and business machines provided the device being con-
trolled is within the electrical limits of the relay.
REPLACEMENT PROCEDURE:
1. CAUTION: Disconnect power supply before servicing equipment.
2. Identify and remove wires from defective relay.
3. Remove defective relay and install Supco replacement.
4. Refer to switch diagrams below and connect wires accordingly.
5. Restore power and check operation.
Caution: Do not exceed contact ratings.
Do not connect power contacts to pilot duty contacts.
Sealed Unit Parts Co., Inc.
PO Box 21 • 2230 Landmark Place • Allenwood, NJ 08720 • USA
Terminals 1 & 2, 4 & 5 are normally closed
Terminals 1 & 3, 4 & 6 are normally open
Supco Coil Terminal Terminals Cross Reference
No. Voltage 1-2-3 4-5-6 Essex/RBM Honeywell
90340 24 power power 90-340 R8222D1014
90341 110/120 power power 90-341 R4222D1013
90342 208/240 power power 90-342 R4222N1021
F235-599
Contact Rating Power Pilot
208/240V 208/240V
120V 277V 120V 277V
Full Load Amps 12 6 - -
Resistive Amps* 15 15 3 3
Locked Rotor Amps 60 35 - -
Horsepower 3/4 3/4 1/10 1/10
*0.75 power factor
1
2
3
4
5
6
General