Chromalox PK471-4 - Manual (Page 2)

MOUNTING
WARNING: Hazard of Electrical Shock. Disconnect
all power before wiring or servicing this control.
1. Electric wiring must be installed in accordance with the
National Electrical Code and with local codes by a qualified
person. WARNING: Use copper conductors only.
2. Entrance for wiring is provided by one 1-inch conduit hole in
top of housing. Wiring to control housing should be in mois-
ture-resistant conduit.
3. Remove cover by removing four screws (see Figures 3 and 4).
4. The Chromalox type WCRT thermostat has an enclosed SPDT
switch and may be wired to open on temperature rise (black
to red) or to close on temperature rise (black to blue). (See
Figure 5.)
5. Connect wires according to wiring diagrams (Figures 6 and 7).
Note: Electrical connections should be made with generous loops
of wire – approximately 6” per lead.
6. Replace cover and cover screws. Tighten screws to 4-5 inch
pounds torque.
7. Note: If load amperage or voltage rating exceeds switch rating
and for 3 phase loads, a contactor must be used. Contactor and
wiring to be supplied by customer (see Figure 7).
WARNING: Non-metallic enclosure requires the use
of ground type hub and a jumper wire for ground-
ing the thermostat.
NOTICE: Thermostat is UL Listed for NEMA-4X areas. For it to
retain this listing the sealed conduit hub must also be so listed.
Example Myers Nos. ST-1, ST-2, STR-1, STR-2 or engineering
equivalent.
WIRING
Note: Do not mount control where it will be subject to vibration
or shock. Do not mount adjacent to a large magnetic contactor,
as vibration and shock will cause thermostat to interact erratically –
resulting in chattering of the contactor.
1. The proper location of a heavy duty room thermostat is impor-
tant to assure good performance.
A. Locate where air circulates freely.
B. Never install on or near outside wall.
C. Keep away from windows or doors.
D. Do not locate too close to strong light or other false source
of heat, such as sunlight, steam lines, etc.
E. If electrical conduit leads into cooler or warmer room, plug
up space around wires in the conduit with rock wool.
2. Use sheet metal or wood screws through the four 1 /
4
” diameter
mounting holes in the housing to mount control. (See Figure 2.)
3. WARNING: Any deformations of bulb or capillary
that result in leakage of fluid from control ren-
ders control inoperative.
Figure 2
Dimensions
1 1 / 2 ”
1” Dia.
3 5 /
16
”
6 1 /
4
”
2 3 /
8
”
1 / 4 ” Dia. (4 Places)
2 15 /
16
”
2 3 /
4
”
3 /
4
”
7”
5 7 /
8
”
3 1 /
2
”