FHD-UL

ELECTRIC DEFROST — 208/230/1/60 — (2) UNIT COOLERS / TIMER ONLY IMPORTANT WIRING NOTES - INSTALLER PLEASE READ CAREFULLY! Sub-circuit fusing or service disconnect switches are not shown but may be required as per the NEC and / or local codes. It is the responsibility of the installing contractor to interpret and comply with all applicable electrical codes. Field install an 18 GA jumper wire between terminals 3 & 4 on terminal block TB2 of each unit cooler for continuous low speed fan operation (870 RPM). For continuous high speed fan operation (1100 RPM) remove jumper wire. See page 20 for optional two speed fan relay control wiring if required. The defrost time clock and block out relay are typically located in the system condensing unit. All unit cooler power should feed from this unit. When connecting multiple unit cooler defrost heaters to (1) defrost time clock make sure the total heater amp draw does not exceed the defrost timer contact rating (typically 40 resistive amps for an 8145-20 or equivalent timer), Also be sure the wire gauge size is adequate to carry the total amp load required.. If the combined heater amp draw exceeds the defrost timer rating a heater contactor must be installed (see alternate wiring diagram for 1 or 2 heater contactor wiring arrangement). When connecting (2) electric defrost unit coolers to (1) defrost timer remove the black wire from the defrost termination / fan delay control which is factory wired to terminal 2 - TB2 on unit cooler #2 and cap the wire. This will allow the fan delay on unit cooler #1 to control the fans on both unit coolers. When connecting (2) electric defrost unit coolers to (1) defrost timer remove the red wire from the defrost termination / fan delay control which is factory wired to terminal 4 - TB1 on unit cooler #2 and hard wire to a field wire connected to terminal 1 - TB2 on unit cooler #1. This will place the (2) defrost termination controls in series so that both units must reach temperature in order to terminate the defrost cycle. When using a heater contactor with unit cooler defrost heaters factory wired for single phase remove factory installed jumper between terminals 2 & 3 on TB1 and wire directly to heater contactor. The room thermostat and liquid line solenoid valve are shown as field installed but may be factory mounted in the unit cooler. Make sure the solenoid holding coil is wired for the correct control voltage (115 or 230). < + * ** ! ^ FIELD WIRING DIAGRAMS — TYPICAL #