wiring a thermostat relay

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Joined Apr 25, 2011
I am building a greenhouse which I purchased used. It came with a Schaefer Exhaust fan (1ph 230v 3p4w Magnatek Century model CS422 motor pn #8-194052-01, serial BU3-235) and controls consisting of a two-stage thermostat (Esapco T15-2) and a Square D class 8501 Type CO16 (16V20) series C relay.

The t-stat is wired to an enclosure housing the relay. The stat has five wires, 2 - red leads (connected to relay terminals 4 and 1), 2 - black leads (connected to relay terminal 8 and one open lead to connect to ??) and 1 - green (connected to enclosure body).
There is a red jumper off of relay terminal 4 that is open. There is a red open lead from relay terminal 6 as well.

So basically I have three open leads as described and open/unused terminals on the relay nos. 2, 5, and 7.

Based on SQD mfg literature the 16V20 indicates a 120 volt coil.

I have a 4-wire cable being fed from a 2p 15a circuit breaker. The motor had been wired previously with a 14/3 romex that was still terminated in the wiring junction on the motor.

can anyone help or point me in the right direction?

Thank you!!