5D51-35, -78 & -90
WHITE-RODGERS
INSTALLATION INSTRUCTIONS
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.
Fan & Limit Control
DESCRIPTION
This fan and limit control combines, in one enclosure, a
fan switch with an adjustable differential which operates
the blower in a forced warm air furnace and a limit switch
with a fixed differential which automatically shuts off the
burner if the furnace temperature exceeds a predetermined high point.
THIS CONTROL MUST BE INSTALLED BY A QUALIFIED INSTALLER.
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 re-calibrate this control will void the WhiteRodgers warranty.
WARNING
!
Do not use on circuits exceeding specified voltages. Higher voltages will damage control and
could cause shock or fire hazard.
If in doubt about whether your wiring is millivolt,
low or line voltage, have it inspected by a qualified heating and air conditioning contractor or a
licensed electrician.
A summer fan switch is incorporated in this control to
provide a convenient method for manual operation of the
fan for air circulation during the summer.
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.
Label all wires prior to disconnection when servicing controls. Wiring errors can cause improper
and dangerous operation.
Following installation or replacement, follow
appliance manufacturers’ recommended installation/service instructions to insure proper operation.
Removing Cover
To remove cover from control, grasp cover at top and
bottom and pull outward. Grasping the cover by its sides
will make removal more difficult.
Location
1. The bimetal element should not be too close to any
hot surfaces of the heat exchanger. The element
should always be at least 3“ away from any hot
surfaces unless the position has been determined
acceptable by the furnace manufacturer.
WHITE-RODGERS DIVISION
EMERSON ELECTRIC CO.
9797 REAVIS RD., ST. LOUIS, MO. 63123-5398
(314) 577-1300, FAX (314) 577-1517
9999 HWY. 48, MARKHAM, ONT. L3P 3J3
(905) 475-4653, FAX (905) 475-4625
Printed in U.S.A.
INSTALLATION
2. If this is a new application, please consult the original
equipment manufacturer for proper location.
Mounting, For Flush Mounting (Vertical or
Sloping Surface)
1. Insert the element tube into the bonnet and attach
control case with #10 screws. (Two screws, diagonally located, are sufficient.)
2. Replace control cover after wiring and making any
adjustments to the settings.
PART NO. 37-1558B
Replaces 37-1558-1
9714
Wiring
All wiring must conform to local and national electrical codes and ordinances.
Connect in accordance with the wiring diagrams provided by the equipment manufacturer. If none are
provided, the following represents a typical installation.
CAUTION: Line voltage jumper is factory installed on
Jumper
Factory Installed
On Some Models
To Oil Burner
Control Or
Transformer Primary
Limit
Switch
Fan
Motor
Note:Make L1 “HOT” on
Optional Remote
Manual Switch
For Summer Fan
Fan
Switch
Line
120V installation
Diagram Using Limit In Line Voltage Circuit
L1
L2
some models. This jumper must be removed
when limit switch is used in low voltage or
millivolt circuit.
To Low Voltage
Or Millivolt
Burner Circuit
Fan
Motor
Limit
Switch
Fan
Switch
Note:Make L1 “HOT” on
120V installation
Diagram Using Limit In Low Voltage
or Millivolt Circuit
Optional Remote
Manual Switch
For Summer Fan
L1
Line
L2
OPERATION
SUMMER FAN OPERATION
The cover does not have to be removed to access the
lever. To turn the fan on, slide the lever to the left “MAN”
position. To turn the fan off, slide the lever to the right
“AUTO” position.
For automatic operation of the fan during the heating or
cooling season, the lever must be in the “AUTO” position.
SETTING THE DIAL
To set pointers, hold dial securely with one hand and
move the pointers with the other hand. Do not force the
pointers past any stops on the dial even though the dial
may be graduated beyond the stops.
Limit
Move the right hand pointer so that its straight edge
indicates the temperature at which the contacts should
open. The limit pointer should never be set any higher
than the setting recommended by the furnace manufacturer.
Fan
Move the “Fan On” pointer so that its straight edge
indicates the temperature at which the fan contacts should
close to start the blower. Move the “Fan Off” pointer so that
its straight edge indicates the temperature at which the
fan contacts should open to stop the blower.
Left Hand
Pointer
(Fan Off)
MAN
Center
Pointer
(Fan On)
AUTO
Right Hand
Pointer
(Limit Opens)
0
0
2
2
0
5
5
0
1
0
0
1
0
5
FAN LIMIT
HOLD DIAL WHEN
CHANGING INDICATORS
DO NOT ADJUST
SAFETY STOP
3
0
0
Limit Stop