Thomas & Betts BE, FE Electrical Supply and Connections, Thermostat and Thermostat Connections

Two Screw Terminal Connector Strip for 24-volt Wiring

Figure 11 -

Four Screw Terminal Connector Strip for 24- Volt Wiring

(Paragraph 12 continued on page 16.) Mfg P/N 98807 Rev 8, Page 11

Figure 10 -

Figure 9B

If equipped with unit- mounted disconnect switch, on/ off toggle switch is near access panel to electrical supply junction box.

Circuit breaker button for Option AI-1 unit- mounted disconnect switch

Before attempting to measure or adjust manifold gas pressure, the inlet (supply) pressure must be within the specified range for the gas being used both when the heater is in operation and on standby. Incorrect inlet pressure could cause excessive manifold gas pressure immediately or at some future time.

Instructions to Check Manifold Pressure:

1)With the manual valve (on the combination valve) positioned to prevent flow to the main burners, connect a manometer to the 1/8" pipe outlet pressure tap in the valve. NOTE: A ma- nometer (fluid-filled gauge) is recommended rather than a

spring type gauge due to the difficulty of maintaining calibration of a spring type gauge.

2)Open the valve and operate the heater. Measure the gas pressure to the manifold. Normally adjustments should not be necessary to the factory preset regulator.

If adjustment is necessary, set pressure to correct settings by turning the regu- lator screw IN (clockwise) to increase pressure. Turn regulator screw OUT (counterclockwise) to decrease pressure.

Consult the valve manufacturer's literature provided with the heater for more detailed information.

11. Electrical Supply and Connections

All electrical wiring and connections, including electrical ground- ing MUST be made in accordance with the National Electric Code ANSI/NFPA No. 70 (latest edition) or, in Canada, the Ca- nadian Electrical Code, Part I-C.S.A. Standard C22.1. In addi- tion, the installer should be aware of any local ordinances or gas company requirements that might apply.

Check the rating plate on the heater for the supply voltage and current requirements. A separate line voltage supply with fused disconnect switch should be run directly from the main electri- cal panel to the heater. All external wiring must be within ap- proved conduit and have a minimum temperature rise of 60oC. Conduit from the disconnect switch must be run so as not to interfere with the service panels of the heater.

The electrical supply connects at the top back of the heater in the left corner (left when facing the back of the heater). A threaded hole is provided for a standard 1/2" electrical fitting.

The wiring access panel is easily removed for field connections. Consult the wiring diagram supplied with your heater. Replace the panel after the wiring connections are made.

If the heater has field-installed options that require electrical con- nections, consult the instruction sheet and wiring diagram sup- plied in the option package.

A fan-type heater may be equipped with a built-in fused discon- nect switch (Option AI-1). If the heater is equipped with a built- in disconnect switch, a two-position toggle (on/off) switch is located near the electrical supply access panel (See Figures 9A and 9B). This switch may be used to disconnect the power when servicing the heater other than in the supply junction box.

Specific wiring diagrams that include standard and factory-in- stalled options are included with the heater. Check the wiring diagram to identify optional equipment.

WARNINGS: On a heater with a unit disconnect switch (Option AI-1), if the power is turned off at the switch, the supply lead in the electrical supply junction box (Figure 9A) remains energized. If service is to be done in the supply junction box, turn off the power at the remote disconnect switch.

If you turn off the power supply, turn off the gas.

The operating sequence of the heater can be found on the heater wiring diagram and is pub- lished in Paragraph 24, Check Installation and Start-Up. Typical wiring diagrams are on the next four pages, showing standard single- stage heating with spark pilot with and with- out lockout.

CAUTION: If any of the original wire as

supplied with the appliance must be replaced, it must be replaced with wiring material having a temperature rating of at least 105oC, except for limit control and sensor lead wires which must be 150oC. See Hazard Levels, page 2.

12. Thermostat and Thermostat Connections

A thermostat is not standard equipment but is an installation requirement. Use either an optional thermostat available with the heater or a field-supplied

Field Wiring from Disconnect in Conduit

Threaded

Hole for

Standard 1/2"

Fitting

Note: Fan-type heaters with optional built-in disconnect switch, have an on/off switch located near the electrical supply access panel.

Remove

Access Panel to make connections

thermostat. Install according to the thermostat manufacturer's instructions. Make sure that the heat anticipator setting on the thermostat is in accordance with the amperage value noted on the

wiring diagram of your heater. Terminal Strip Connections - The standard heater is equipped with a two- screw terminal connector strip (See Fig-

ure 10) for easy connection to the low voltage controls (24V). When factory-

installed options require two-stage thermostat control, the heater is equipped with a SP-ST relay and a four-screw terminal connector strip (See Figure 11).

If your heater requires field instal- lation of the four-screw terminal strip and the relay, follow the in-

Figure 9A - Electrical Connections

structions packaged with the relay or thermostat option.