1A66/1A66W
ELECTRIC-HEAT THERMOSTAT
(Double Line Disconnect)
WHITE-RODGERS
INSTALLATION INSTRUCTIONS
Operator: Save these instructions for future use!
FAILURETOREADANDFOLLOWALLINSTRUCTIONSCAREFULLYBEFORE
INSTALLING OR OPERATING THIS CONTROL COULD CAUSE PERSONAL
INJURY AND/OR PROPERTY DAMAGE.
DESCRIPTION
The Type 1A66/1A66W Electric Heat Thermostat is de-
signed for use on all types of electrical heating installa-
tions such as cable heat, baseboards, wall insert heaters,
etc. Its narrow operating differential and the ability of its
fully exposed knob to sense both radiant heat and room
air temperature make this control ideal for use on such
installations.
NOTE: Only one side of line is broken during normal cycling of
this thermostat.
60
70
50
The Type 1A66/1A66W is intended for use on 240 or 277
volts where local codes require that a double line discon-
nect thermostat be used.
80
OFF
Dial Setting: Knob may be set anywhere between 40°
and 85°F by simply turning knob so that indicator on knob
points to the desired setting.
The knob may be turned past 40° to the “OFF” position to
obtain temporary shutdown of the heating equipment for
short periods of time such as on weekends, vacation, etc.
Turning knob to “OFF” position will break both sides of line.
PRECAUTIONS
This control is a precision instrument, and should be All wiring must conform to local and national electrical
handled carefully. Rough handling or distorting compo-
nents could cause the control to malfunction. Take care
not to push or damage the knob sensing element
during installation.
codes and ordinances.
WARNING
Do not use on circuits exceeding specified volt-
ages. Higher voltages will damage control and
could cause shock or fire hazard.
CAUTION
To prevent electrical shock and/or equipment
damage, disconnectelectricpower tosystem, at
mainfuseorcircuitbreakerbox,untilinstallation
is complete.
Do not use on inductive loads. Inductive (motor)
loadswilldamagecontrolandcouldcauseshock
or fire hazard.
SPECIFICATIONS
Temperature Range: 40° to 85°F
Differential: 1°F
Switch Rating: Non-Inductive
22A (5000W) 240VAC
18A (5000W) 277VAC
Switch Action: Open on rise
Contact Structure: Double Line Disconnect - DPST
INSTALLATION
If the heating equipment manufacturer has made provi- 3. It should be mounted as far as possible from undesir-
sions or recommendations for the location of this control,
thenfollowthoseinstructions. Ifnot, thefollowingsugges-
tions should be observed.
able sources of heat and cold such as:
a. Windows and doors
b. Direct rays from sun
1. The control should be mounted in the wall, approxi-
mately five feet from the floor, as near as possible to
the centre of the controlled area.
c. Hot water or cold water pipes
d. Adjoining outside walls
2. It should be mounted on a partitioning wall, not on an
outside wall.
WHITE-RODGERS DIVISION
EMERSON ELECTRIC CO.
9797 REAVIS RD., ST. LOUIS, MO. 63123
(314) 577-1300, Fax (314) 577-1517
PART NO. 37-5428C
Replaces 37-5428B
9724
Printed in U.S.A.
9999 HWY. 48, MARKHAM, ONT. L3P 3J3
(905) 475-4653, FAX (905) 475-4625
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