Chromalox WR-80EP specifications General, Mounting

Installation

and

OPERATION INSTRUCTIONS

4	WR
(Supersedes PK435-4)	PK435-5

161-048630-001

JUNE, 1994

Type WR-80EP Explosion Proof Room Thermostat

21/2”

Specifications – Table A

		Temp.			Maximum Rating
		Range
	Model	(°F)	120V a-c	† 115V d-c	240V a-c	† 230V d-c	277V a-c	480V a-c
				125Va pilot		125Va pilot		125Va pilot
	WR-80EP	40-90	25 amps	duty (use	22 amps	duty (use	18 amps	duty (use
			or 3000	with d-c	or 5280	with d-c	or 5000	with a-c
61/8”
			total watts	contactor)	total watts	contactor)	total watts	contactor)

† d-c ratings not UL listed

WR-80EP 40 to 90°F UL Listed

4”

311/16”

GENERAL

Positive accuracy, long and reliable service, 3° differential. Heavy- duty, single stage, SPST line voltage snap-acting switch. Patented hydraulic element. WR-80EP has external, coiled sensing element and a low position which drops control point to keep heater off.

Uses — Automatically controls room temperature by turning electric air heaters on and off. Can be used to control the air heaters directly, within thermostat rating. For higher ratings use thermostat with mag- netic contactor. Place thermostat on inside wall, away from undue heating or cooling influences, about 4 feet above the floor. The explo- sion proof WR-80EP is suitable for Class I, Group D and Class II, Groups E, F and G locations.

NOTICE: Type WR thermostats are designed for temperature control service only. Because they do not fail safe, they should not be used for temperature limiting duty.

WARNING: Users should install adequate back-up con- trols and safety devices with their electric heating equipment. Where the consequences of failure may be severe, back-up controls are essential. Although the safety of the installation is the responsibility of the user, Chromalox will be glad to assist in making equipment recommendations.

Principle of Operation — Control action of these thermostats is pro- vided through the principle of liquid volume change. With a variation in temperature, the liquid in the sensing element expands or contracts, causing a bellows to actuate the switching mechanism.

Housing — The control housing and cover assembly is of heavy-duty cast aluminum.

MOUNTING

Note: Do not mount control where it will be subject to vibration, shock, grease, dust, lint or corrosive vapors. Do not mount adjacent to a large magnetic contactor, as vibration and shock will cause thermo-

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

stat to interact erratically – resulting in chattering of the contactor.

WARNING: Do not twist or uncoil the coiled element on top of the case.

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.

Figure 1

311/16

45/8

111/16

11/16

4 61/8

5/8	215/16	1
4-Holes		1 /16
5/16" Dim.	5
	4 /8	1/2 -14
		N.P.T. Thread

© 2010 Chromalox, Inc.