Chromalox PK410-1 installation instructions Mounting, Wiring, Calibration

MOUNTING

Note: Do not mount control where it will be subject to vibration, shock, grease, dust, lint or corrosive vapors. Do not mount adja- cent to a large magnetic contactor, as vibration and shock will cause thermostat to interact erratically – resulting in chattering of the contactor.

CAUTION: Do not twist or uncoil the coiled element on top of the case of the WR-90.

The proper location of a heavy duty room thermostat is important to assure good performance.

1.Locate where air circulates freely.

2.Never install on or near outside wall.

3.Keep away from windows or doors.

4.Do not locate too close to strong light or other false source of heat, such as sunlight, steam lines, etc.

5.If electrical conduit leads into cooler or warmer room, plug up space around wires in the conduit with rock wool.

WIRING

CAUTION: Hazard of Electric Shock. Disconnect all power before wiring or servicing this control.

1.Electric wiring to heater must be installed in accordance with National Electrical Code and with local codes. WARNING:

Use copper conductors only.

Connect wires according to wiring diagrams (Figures 1 and 2). Note: Electrical connections should be made with generous loops of wire – approximately 6” per lead.

Note: If load amperage or voltage rating exceeds switch rating, a contactor must be used. Contactor and wiring to be supplied by customer. (See Figure 2)

Figure 1 — Single phase loads when load does not exceed	Figure 2 — Single phase loads when load exceeds rating of thermostat and
rating of thermostat.	three phase loads.

CALIBRATION

CAUTION: Hazard of Electric Shock. Extreme care should be exercised during calibration adjustments because of shock hazard due to exposed electrical terminals.

WR-80 thermostats are accurately calibrated at the factory so the dial setting correctly indicates the temperature at which the contacts open on temperature rise. If, as a result of damage in tran- sit or for other reasons the room temperature differs appreciably from the dial setting, the calibration may be adjusted as follows:

1.Note temperature on thermometer.

2.Set dial at highest temperature.

3.Turn dial slowly to lower temperature and stop when thermo- stat contacts open.

4.Loosen screw at bottom of thermostat and remove thermostat from mounting plate.

5.On back of thermostat, loosen two dial screws (Figure 3). Carefully turn the dial only to correct temperature setting as indicated by thermometer. Be sure the thermostat shaft is not moved during this operation.

6.Tighten the dial screws and replace thermostat.

Figure 3