White Rodgers 151 User Manual

CAUTION

WHITE-RODGERS

Operator: Save these instructions for future use!

FAILURE TO READ AND FOLLOW ALL INSTRUCTIONS CAREFULLY BEFORE
INSTALLING OR OPERATING THIS CONTROL COULD CAUSE PERSONAL
INJURY AND/OR PROPERTY DAMAGE.

These room thermostats have been designed for control­ling cooling equipment operating on line voltage with
heavy electrical loads. They are suitable for operation of
unit coolers, room coolers, etc., or any similar refrigera­tion application requiring a heavy duty room thermostat.

Models are available with various ranges for meeting the
needs of almost any application.

THESE CONTROLS MUST BE INSTALLED BY A
QUALIFIED INSTALLER.

Do not exceed the specification ratings.
All wiring must conform to local and national electrical

codes and ordinances.
This control is a precision instrument, and should be

handled carefully. Rough handling or distorting compo­nents could cause the control to malfunction.

This control has been accurately calibrated at the factory.
Any attempt to calibrate this control will void the White­Rodgers warranty.

The proper location of a heavy duty room thermostat is
very important to assure good performance. The following
general rules will help in determining the proper location:

1. Make sure that it is in a place where air circulates
around it freely. This is important.

2. Never install it on or near an outside wall.

3. Keep it away from windows or doors.

4. Don’t locate it too close to a strong light or any other
false source of heat such as direct sunlight, steam
lines, etc.

5. Mount it on a post or a partitioning wall, but make sure
that there are no pipes or duct work in that wall or
directly behind it.

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

TYPE 151

ROOM THERMOSTAT

Cooling Service, External Dial

INSTALLATION INSTRUCTIONS

DESCRIPTION

W

H

I

T

E

-

R

S

O

R

D

E

G

90

70

80

50

60

40

PRECAUTIONS

To prevent electrical shock and/or equipment
damage, disconnect electric power to system, at
main fuse or circuit breaker box, until installation
is complete.

WARNING

Do not use on circuits exceeding specified volt­ages. Higher voltages will damage control and
could cause shock or fire hazard.

INSTALLATION

CONCRETE

PLASTER

JUNCTION BOX

THERMOSTAT

CONDUIT

INSIDE WALL

CONDUIT
ALONG WALL

WALL INSTALLATION

The mounting plate for this thermostat has two

5

holes 3

/16”apart for attaching the control on a

standard switch box.

Figure 1

WHITE-RODGERS DIVISION

EMERSON ELECTRIC CO.
9797 REAVIS RD., ST. LOUIS, MO. 63123
[phone], FAX [phone]

9999 HWY. 48, MARKHAM, ONT. L3P 3J3
[phone], FAX [phone]

Printed in U.S.A.

PART NO. 37-1118B

Replaces 37-1118

9548

INSTALLATION CONT.

70

60

80

INDICATING

LINE

IMPORTANT

When control is located where ambient temperature is
below freezing, choose a control location far enough
away from doors and windows so that moisture will not
condense on control.

If the thermostat is used with unit coolers, the following
suggestions may help. (See Fig. 2).

1. Position “A” is good if it is sufficiently close to the unit
cooler so that the return air to the cooler flows over the
thermostat.

2. Position “B” is good if it is not necessary to make
frequent adjustments of the dial setting.

3. Position “C” is all right if it is sufficiently far from the
cooler that air flowing over the thermostat is not much
above the average room temperature.

4. In general, position “D” is not advisable because the
post may prevent air from circulating over the thermo­stat.

CEILING

POST

UNIT

B

D

C

RETURN AIR

FLOOR

Figure 2

PARTITION
WALL OR POST
DIRECTLY
BEHIND UNIT

A

WIRING

All wiring should be done in accordance with local and national electrical codes and ordinances.

If the manufacturer of the cooling equipment has supplied a wiring diagram, follow the manufacturer’s recommenda­tions. The following diagrams show the general use of these controls.

TEMPERATURE

CONTROL

TO LINE SWITCH

AND POWER SUPPLY

HOT
GND

Circuit showing temperature control to open and
close refrigerant valve. Suction pressure control
starts and stops compressor through motor starter.

HIGH SIDE

PRESSURE CONTROL

(IF USED)

MOTOR

STARTER

Circuit showing temperature control con­trolling compressor directly.

TO LINE SWITCH

AND POWER SUPPLY

HIGH SIDE

PRESSURE

CONTROL

SUCTION

PRESSURE

CONTROL

TEMPERATURE

CONTROL

SOLENOID

REFRIGERANT

VALVE

SETTING THE DIAL

To set the dial, simply move it so that the indicating line on
the case points to the temperature at which the contacts
are to open as the temperature drops.

2