(Double Line Disconnect)
Operator: Save these instructions for future use!
INSTALLING OR OPERATING THIS CONTROL COULD CAUSE PERSONAL
INJURY AND/OR PROPERTY DAMAGE.
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
NOTE: Only one side of line is broken during normal cycling of
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.
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.
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
codes and ordinances.
Do not use on circuits exceeding specified volt-
ages. Higher voltages will damage control and
could cause shock or fire hazard.
To prevent electrical shock and/or equipment
damage, disconnectelectricpower tosystem, at
Do not use on inductive loads. Inductive (motor)
or fire hazard.
Temperature Range: 40° to 85°F
Switch Rating: Non-Inductive
22A (5000W) 240VAC
18A (5000W) 277VAC
Switch Action: Open on rise
Contact Structure: Double Line Disconnect - DPST
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
EMERSON ELECTRIC CO.
9797 REAVIS RD., ST. LOUIS, MO. 63123
(314) 577-1300, Fax (314) 577-1517
PART NO. 37-5428C
Printed in U.S.A.
9999 HWY. 48, MARKHAM, ONT. L3P 3J3
(905) 475-4653, FAX (905) 475-4625