INSTALLATION AND OPERATION MANUAL
EPET SERIES EXPLOSION PROOF THERMOSTATS
The Columbus Electric EPET Series thermostat is designed to control heating only, cooling only,
heating and cooling or ventilation systems in oil refineries, grain elevators, munitions plants, hospital
operating rooms and other hazardous locations.
The switching mechanism is enclosed in a 1/2” thick cast aluminum case which is dust proof and dust
resistant. A reliable sensing element provides accurate response to temperature change and does not
require leveling during installation.
The casing is tapped top and bottom for 3/4” conduit. A 1/2” adapter is included.
SPECIFICATIONS
Electrical Ratings: 22 Amp @ 125 - 277 VAC
3/4 HP @ 125VAC
1 1/2 HP @ 250 - 277 VAC
Differential : Heat- 2
°
F / Cool- 4
°
F
Dimensions: 5.62” x 6.37” x 4.43”
Approvals:
UL and CSA
Class I Groups C & D
Class II Groups E, F & G
Temperature adjustment range: 50-90
°
F
INSTALLATION
ALL WIRING MUST COMPLY WITH NFPA-70 (NEC), LOCAL AND STATE CODES.
Locate the thermostat approximately five feet (5’) above the floor in a location that will best sense the
average temperature of the area to be controled. Do not mount the thermostat adjacent to water pipes,
in drafty areas, or other locations that would adversely affect the operation of the thermostat.
1)
Remove the thermastat cover assembly from the base by removing the four corner screws.
Set the cover assembly aside.
CAUTION: Marring of the mating surfaces of the enclosure
could destroy the integrity of the seal causing unsafe conditions during thermostat
operation.
2)
Mount the thermostat base on the surface selected. See Fig. 1 for dimensions.
3)
The base is tapped for 3/4” conduit; a 1/2” conduit adapter and a 3/4” plug is provided.
Two threaded openings are provided for wiring. Unused openings must be properly plugged
with the plug provided prior to applying power to the unit.
4)
Connect the conduit to the mounted base and pull the required wires into the base.
5)
Connections are to be made to the switch terminals on the rear of the cover assembly. See
Fig. 2. The cover assembly can then be attached to the base using the four mounting screws.
TIGHTEN TO A MINIMUM OF 40 INCH POUNDS.
6)
The installer must seal each conduit run within 18” of the thermostat enclosure. This seal
must be a suitable, listed hazardous location fitting.
FORM: 8069
REV. -
