8A18Z-2
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.
This Evaporative Cooler Control has a rain-proof enclosure and can be used with either 120 VAC or 240 VAC
systems. It was designed for use with the White-Rodgers
1F51-619 or 1F51W-619 Thermostat to provide automatic temperature and ventilation control and remote fan
speed selection of an evaporative cooler with 2-speed
fan. The pump relay is automatically operated to allow
wetting of cooler pads before starting fan.
Evaporative Cooler Control
INST ALLA TION INSTRUCTIONS
DESCRIPTION
If in doubt about whether your wiring is millivolt, line, or low
voltage, have it inspected by a qualified heating and air
conditioning contractor, electrician, or someone familiar
with basic electricity and wiring.
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.
PRECAUTIONS
CAUTION
!
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 voltage. Higher voltage will damage control and could
cause shock or fire hazard.
WHITE-RODGERS DIVISION
EMERSON ELECTRIC CO.
9797 REAVIS ROAD
ST. LOUIS, MISSOURI 63123-5398
Printed in U.S.A.
PART NO. 37-5918B
Replaces 37-5918A
9909
SPECIFICATIONS
Case
Panel
Cover
Flat washers
Bolts
Mounting holes
for four bolts
and washers
Panel mounting
screws
Cover
screw
Figure 2. Installing control
Electrical Ratings:
Input Voltage: 120 or 240 VAC, 60 Hz.
Operating Ambient Temperature Range:
40 to 150°F (5 to 65°C)
Power Consumption:
6 Watts nominal with all three relays energized
Fan Rating:
12 FLA., 72 LRA; 120 VAC
6 FLA., 36 LRA; 240 VAC
Pump Rating:
10 FLA., 60 LRA: 120 VAC
5 FLA., 30 LRA; 240 VAC
The 8A18Z-2 Evaporative Cooler Control consists of
three relays and a low voltage transformer with dual
voltage primary. The pump relay is automatically operated, which allows the cooler pads to become wet before
the fan starts. This will eliminate the fan from blowing dust,
warm air, and odor on initial start-up. The fan relay
controls operation of the fan without the pump when the
thermostat subbase is in the vent position, and controls
operation of both fan and pump when the thermostat
subbase is in the cool position.
Combined Total Connected Load:
16 FLA., 120 VAC
8 FLA., 240 VAC
Mounting:
Four9⁄32” Dia. holes
(21⁄2” x 5” center line to center line)
Dimensions:
6” wide x 8” high x 3” deep
Line
connections
N
L2
120V
120V
120V
240V
240V
P2
240V
F2
P1
Fan timer
relay
Pump
connections
Fan
connections
P2
F2
L1
LO
HI
Figure 1. Panel assembly
8A18Z-2
R
W
Y
G
Low voltage
transformer
Pump relay
Low voltage
thermostat
connections
Fan
speed
relay
INSTALLATION
1. Remove cover screw. To remove cover, pull cover
outward at the top, then lift cover off the locating tabs
at the bottom of the case.
2. Remove panel assembly from case and discard packing material.
NOTE
Place panel assembly in a safe location to prevent damage to the panel while installing the case.
3. Determine which knockouts will be used for electrical
conduits, then remove electrical knockouts from case
before mounting.
If the larger knockout is to be removed, remove the
smaller knockout before removing the larger one.
4. To remove the knockouts, place a screwdriver on
the knockout at the location indicated by the arrow
(see fig. 3). Tap the screwdriver to pop the knockout
out of the case. If the knockout is not completely
removed, carefully use pliers to twist the knockout
until it comes out.
NOTE
Figure 3. Electrical knockouts
2