Input Wiring - heat-timer EPU-D Installation And Operation Manual

18 EPU‐D Installation and Operation Manual
Input Wiring
To avoid damage to the EPU‐D, NO VOLTAGE can be applied to the EPU‐D input
terminals.
Class 2 voltage wiring (low‐voltage sensor and communication wires) must use
a different enclosure knockout and conduit than any Class 1 voltage wiring.
Wiring the Heating System Sensor
NOTES:
• Use only the provided Heat‐Timer heating system sensor (p/n 904220‐00). See page 8 for a
description of the sensor.
• For acceptable sensor locations, see "Piping Diagrams" on page 38.
1. Run the System Temperature Sensor wires through a knockout located on the bottom of
the EPU‐D enclosure.
NOTE: The sensor wires can be extended up to 500 feet (152.5 meters) using an 18 AWG
shielded 2‐conductor cable (Heat‐Timer p/n 703001‐01 or equivalent #18/2 cable).
2. Connect the System Temperature Sensor wires to terminals 9 and 10 on the EPU‐D.
3. Connect the shield to terminal 10 on the EPU‐D.
NOTE: Do not connect the shield at the sensor end.
Wiring an Optional Pressuretrol Sensor
NOTES:
• Heat‐Timer does not provide a Pressuretrol sensor.
• The optional Pressuretrol sensor must be a reverse‐acting sensor. See page 8 for a description of
the sensor.
• For acceptable sensor locations, see "Piping Diagrams" on page 38.
1. Connect wires to the Pressuretrol normally‐closed terminals.
2. Run the wires from the Pressuretrol through a knockout located on the bottom of the EPU‐D
enclosure.
NOTE: The sensor wires can be extended up to 500 feet (152.5 meters) using an 18 AWG shielded
2‐conductor cable (Heat‐Timer p/n 703001‐01 or equivalent #18/2 cable).
3. Connect the Pressuretrol wires to terminals 9 and 10 on the EPU‐D.
4. Connect the shield to terminal 10 on the EPU‐D.
NOTE: Do not connect the shield at the sensor end.
059840‐00 Rev. A
CAUTION
Heat‐Timer Corp.