heat-timer Digi-span SPC TEMP Installation & Operating Instructions Manual

INSTALLATION/OPERATING INSTRUCTIONS

R

SPC TEMP

Digital Set Point Control

Temperature Range -30 to 250°F (-35 to 120°C)

Output light indicates

status of relay

Push this button to display

the set point or differential

Wire sensor provided with

the unit to these terminals

Digital display reads
sensor value constantly

OUTPUT

= Set Point
= Differential

= Shorted Sensor
= Open Sensor

SENSOR 24VAC

UP
PRESS TO READ
DOWN

(+) (-)

To use 12VDC connect
to these terminals
observing the polarity

Black

Blue
Blue

Output

wires

Red

White

To use 120VAC
power connect to
these wires

Push these buttons to adjust
the set point or differential

To use 24VAC power
connect to these two
terminals

Warning: This Heat-Timer control is strictly an operating control; it should never be used as a primary
limit or safety control. All equipment must have its own certified limit and safety controls required by local
codes. The installer must verify proper operation and correct any safety problems prior to the installation
of this Heat-Timer control.

This Heat-Timer device was thoroughly tested for defects and workmanship before leaving our factory. We do warrant the equipment to
be free of defects under normal use for a period of one year from the date of installation. Transportation charges for factory repairs must
be prepaid. Damage to the Heat-Timer device or any of its components due to misuse, abuse, improper installation, or caused by power
failures, fire, flood, or lightning are not covered by this warranty. The company assumes no liability for indirect or consequential damages
of any nature. This Heat-Timer warranty applies only to the original purchaser/user, is not assignable or transferable, and does not cover
damage to the device occurring in shipment. Any service, repairs, modifications or alterations to the unit not expressly authorized by the
company will invalidate the warranty. This warranty is in lieu of all other warranties expressed or implied.

LIMITED ONE YEAR WARRANTY

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INSTALLATION

Mounting the Controller

• The SPC is designed to mount on a 1900 (4”x4”) electrical box.

• If the SPC is to be panel mounted, or if additional room is needed for wiring, an extension skirt is available*.

• Locate the SPC in a convenient location near the unit to be controlled.

• Mount the unit away from excessive heat or cold. Ambient operating temperature is from 20 to 120°F .

• After completing all the wiring connections (see below) use the two screws provided to mount the SPC to the 1900 box.

Installing the T emperature Sensor

• The temperature sensor wires can be extended up to 500’ by splicing with 18 gauge shielded wire.

• Do not run wires in conduit with line voltage.

• If measuring liquid temperature, the sensor should be inserted into a 3/8” ID well (HT#904011 or equivalent).

• The SPC will operate based on the temperature it reads at the sensor location. Therefore, select a sensor location which is
representative of the entire system.

Wiring the Sensor

• The sensor wires can be connected to the two screws on the front of the SPC marked SENSOR.

• The wires can also be connected to the rear of the SPC using the Rear Wire connector*. Connect the sensor wires to the
orange and yellow wires from the Rear Wire connector .

• Polarity is not important. Either wire from the sensor can be connected to either SPC sensor input.

Wiring the Power - SPC can use either 120VAC, 24VAC, or 12VDC

120V AC

• Attach line voltage to the two blue wires extending from the back of the SPC.

• Use wire nuts, or wrap the connections with electrical tape.

• Class 1 voltages must enter the enclosure through a different opening from any Class 2 wiring.

24V AC

• Use a dedicated transformer with at least a 5VA output.

• Bring 24VAC to the two screws on the front of the SPC marked 24V AC

• 24VAC can also be connected to the rear of the SPC using the Rear Wire connector*. Connect the 24VAC to the violet and
gray wires from the Rear Wire connector .

12VDC

• The polarity of the connection is important. If the polarity is reversed, the SPC will not be damaged. However, it will not
operate unless the polarity is corrected.

• Bring the (+) side of the 12VDC to the inner screw marked 24V AC (see front page). Bring the (-) side of the 12VDC to the
outer screw marked 24V AC.

• 12VDC can also be connected to the rear of the SPC using the Rear Wire connector*. The (+) side of the 12VDC must be
connected to the connector’s violet wire. The (-) side of the 12VDC must be connected to the connector’s gray wire.

* The Optional Mounting Kit

includes the extension skirt,
the Rear Wire connector , and
an input terminal cover. Order
separately as HT #908520.

SENSOR

TYPICAL WIRING DIAGRAM

WHITE

RED

BLACK

UNIT

POWER

HOT

NEUTRAL

WARNING

The SPC can accept only one
source of power: 120VAC,
24V AC, or 12VDC. If more than
one power source is applied, the
unit may be damaged.

24 VAC

12VDC

or wire 120VAC to rear

transformer (Blue Wires)

HEATER

or CHILLER

UNIT

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