Chromalox PK410-1 Manual De Usuario
PK410-1
161-048634-001
JUNE, 1989
4WR
Installation Instructions
(Supersedes PK410)
Type WR Room Thermostat
© 2010 Chromalox, Inc.
Specifications – Table A
GENERAL
Positive accuracy, long and reliable service, 3° differential.
Heavy-duty, single stage, SPST line voltage snap-acting switch.
Patented hydraulic element. WR-80 has internal sensing element
and thermometer on cover; WR-90 has external, coiled sensing
element but no thermometer. Both have a low position which
drops control point to keep heater off. WR-80 and WR-90 fin-
ished in tough metallic gray with chrome trim; mounting plate
fits outlet or conduit box.
Uses – Automatically controls room temperature by turning elec-
tric air heaters on and off. Can be used to control the air heaters
directly, within thermostat rating. For higher ratings use thermo-
stat with magnetic contactor. Place thermostat on inside wall,
away from undue heating or cooling influences, about 4 feet
above the floor. WR-90 is especially useful in holding lower tem-
peratures, for example, in garages, warehouses, factories, etc.
Patented hydraulic element. WR-80 has internal sensing element
and thermometer on cover; WR-90 has external, coiled sensing
element but no thermometer. Both have a low position which
drops control point to keep heater off. WR-80 and WR-90 fin-
ished in tough metallic gray with chrome trim; mounting plate
fits outlet or conduit box.
Uses – Automatically controls room temperature by turning elec-
tric air heaters on and off. Can be used to control the air heaters
directly, within thermostat rating. For higher ratings use thermo-
stat with magnetic contactor. Place thermostat on inside wall,
away from undue heating or cooling influences, about 4 feet
above the floor. WR-90 is especially useful in holding lower tem-
peratures, for example, in garages, warehouses, factories, etc.
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.
CAUTION: Users should install adequate back-up controls 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 responsi-
bility of the user, Chromalox will be glad to make equipment rec-
ommendations.
Principle of Operation – Control action of these thermostats is
provided 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.
control service only. Because they do not fail safe, they should
not be used for temperature limiting duty.
CAUTION: Users should install adequate back-up controls 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 responsi-
bility of the user, Chromalox will be glad to make equipment rec-
ommendations.
Principle of Operation – Control action of these thermostats is
provided 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.
CAUTION: Not for use in hazardous environments
as described in National Electrical Code. Failure to
comply can result in explosion or fire.
as described in National Electrical Code. Failure to
comply can result in explosion or fire.
WR-80
40 to 80°F
UL Listed
Maximum Rating
Range
Model
(°F)
120Vac
† 115Vac
240Vac
† 230Vac
277Vac
480Vac
WR-80
40-80
125va pilot
125va pilot
125va pilot
25 amps
duty (use
22 amps
duty (use
18 amps
duty (use
WR-90
20-90
or 3000
with d-c
or 5280
with d-c
or 5000
with a-c
total watts
contactor)
total watts
contactor)
total watts
contactor)
WR-90
20 to 90°F
UL Listed
† d-c ratings not UL listed
5
3
/
8
”
2
1
/
2
”
2
1
/
4
”
2
9
/
16
”
6”
2
3
/
4
”
2
1
/
2
”
Note —
WR-80 is
not a
Fail-Safe
Device.
WR-80 is
not a
Fail-Safe
Device.