White Rodgers 37-1896C User Manual

INDUSTRIAL

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.

White-Rodgers Industrial Temperature Controls are suit­able for most high temperature applications.

On small electric ovens, these controls may be used to
operate ovens directly. On ovens requiring a current
greater than the capacity of the control, these controls
may be used for controlling the pilot circuits of operating
relays.

These controls may also be used for controlling electri­cally operated gas valves on gas fired equipment.

TEMPERATURE CONTROL

INSTALLATION INSTRUCTIONS

DESCRIPTION

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.

ELECTRICAL DATA
Switch Action: S.P.S.T. – Open on Rise
Switch Rating:

25A. 120V.A.C., 20A. 240V.A.C. NON-IND.

2.9A., 25V.A.C., 120V.A.C.
125V, PILOT DUTY 600V.A.C.

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.

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 volt­ages. Higher voltages will damage control and
could cause shock or fire hazard.

SPECIFICATIONS

THERMAL DATA
Range: 100° to 500°F (38° to 260°C)
Differential: 15°F (8°C) Fixed
Capillary Length: 6 Ft. (1.8 m)
Bulb Size: 3/16" x 9-7/8"

PART NO. 37-1896C

Replaces 37-1896B & 37-9103

9548

INSTALLATION

For all normal installations, the sensitive bulb should be located
so as to be in the average temperature of the controlled medium
where there is a good air circulation around the bulb. The bulb
should not be attached directly to a wall or surface, but should
be held away by mounting brackets. A minimum amount of
capillary should be in the controlled area.

The bulb may be mounted in any normal atmosphere, but it
should be remembered that the copper element should not be
installed in a corrosive atmosphere such as may be found in
certain applications.

ANTICIPATION

Anticipation is a factor introduced into the performance of a
control to reduce its natural differential. The sensitive bulb of
industrial temperature controls can be located to obtain anticipa­tion by placing it in a position close to the source of the heat. This
causes the sensitive bulb to receive heat quicker than the oven
proper, causing the control to turn the heat off sooner, thus
reducing the differential.

The proper location of the sensitive bulb depends on the
equipment design and can be determined only by trial. Care
should be taken so as not to put the bulb too close to the source
of the heat as this may subject the bulb to damaging tempera­tures.

The switch mechanism may be located in any position provided
that it will not be subjected to a temperature above 150°F.

Excessive capillary should be coiled and secured close to the
switch mechanism and should be handled with reasonable care
to prevent breaking of the seals, kinking or smashing.

CAUTION

Do not dent the sensitive bulb of this control. A
dent or a sharp bend will change the calibration
and cause the control to cycle at a temperature
lower than the dial setting.

Equipment that is controlled by anticipated controls does not
reach its final or constant temperature on the first cycle of the
control. There is a tendency for the temperature to continue to
rise after the control first starts cycling. After several cycles, the
temperature becomes constant. The greater the amount of
anticipation, the greater the tendency toward preliminary up­ward cycling.

The amount of anticipation as measured by the change in
calibration caused by the anticipated location should not exceed
25°. Thus, if the control is set to open the circuit at 300°F, the
temperature, when it becomes constant, should not be lower
than 275°F.

WIRING

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

If the manufacturer of the heating equipment has supplied
a wiring diagram, follow such recommendations.

If none is offered, this diagram shows a suggested circuit.

HOT

LINE

N

Connections for direct control of heaters.

LOAD

SETTING THE CONTROL

CONTROLS WITH A FIXED DIFFERENTIAL

The indicator (B) points to the temperature at which the contacts
open.

To set the control:

Use a screwdriver in the adjusting slot (A) on the front of the
control to rotate dial until the desired temperature at which
the contacts will open is positioned directly under the
indicator (B).

CONTROLS WITH ADJUSTABLE STOPS

CAUTION

Setting stop higher than control being replaced could
cause personal injury and/or property damage.

L1

HOT

LINE

N

Diagram of connections for operating heating

1. Loosen stop screw (E) with enclosed wrench.

2. Set dial to original equipment manufacturer's specification.

3. Without moving the dial, move stop tab (F) against indica­tor.

4. Retighten stop screw (E).

“F” STOP TAB

“E” STOP SCREW

COIL

LOAD

load through a contactor.

“A” ADJUSTING

FIXED DIFFERENTIAL

L2

“B” FIXED

INDICATOR

SLOT

2