Greenheck ERCH - Energy Recovery Unit with Packaged DX (468151) User Manual

Page 7

Energy Recovery Unit with Packaged DX

ELECTRICAL INFORMATION

The unit must be electrically grounded in accordance with the current National Electrical Code, ANSI/NFPA 70 .
In Canada, use current CSA Standard C22 .1, Canadian Electrical Code, Part 1 . In addition, the installer should
be aware of any local ordinances or electrical company requirements that might apply . System power wiring
must be properly fused and conform to the local and national electrical codes . System power wiring is to the
unit main disconnect (door interlocking disconnect switch standard on most units) or distribution block and
must be compatible with the ratings on the nameplate: supply power voltage, phase, and amperage (Minimum
Circuit Amps - MCA, Maximum Overcurrent Protection - MOP) . All wiring beyond this point has been done by
the manufacturer and cannot be modified without affecting the unit’s agency / safety certification .
If field installing an additional disconnect switch, it is recommended that there is at least four feet of service
room between the switch and system access panels . When providing or replacing fuses in a fusible disconnect,
use dual element time delay fuses and size according to the rating plate .
Field Power Connection: Electronic wiring is run through the roof of the unit . All power and control
connections should be run through the floor or side panel .
If power supply is desired through bottom of unit, run the wiring through the curb, cut a hole in the cabinet
bottom, and wire to the disconnect switch . Seal penetration in cabinet bottom to prevent leakage .
The electric supply to the unit must meet stringent requirements for the system to operate properly . Voltage
supply and voltage imbalance between phases should be within the following tolerances . If the power is not
within these voltage tolerances, contact the power company prior to operating the system .
Voltage Supply - See voltage use range on the rating plate . Measure and record each supply leg voltage at all
line disconnect switches . Readings must fall within the allowable range on the rating plate .
Voltage Imbalance - In a 3-phase system, excessive voltage imbalance between phases will cause motors
to overheat and eventually fail . Maximum allowable imbalance is 2% . To determine voltage imbalance, use
recorded voltage measurements in this formula .
Key:

V1, V2, V3 = line voltages as measured

VA (average) = (V1 + V2 + V3) / 3

VD = Line voltage (V1, V2 or V3) that deviates farthest from average (VA)

Formula: % Voltage Imbalance = [100 x (VA-VD)] / VA

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.

WARNING

To prevent injury or death due to electrocution or

contact with moving parts, lock disconnect switch

open.

WARNING

For units with a gas furnace, if you turn off the

power supply, turn off the gas.

OUTDOOR AIR WEATHERHOOD

Outdoor air weatherhood will be factory mounted .

EXHAUST WEATHERHOOD

The exhaust weatherhood is shipped separately as a kit with its own instructions .

DAMPERS

Backdraft dampers are always included as an integral part of the exhaust hood
assemblies . Motorized outdoor air and exhaust air dampers are optional and are
factory mounted (and wired) at the intake .

Most factory supplied electrical components are pre-wired . To
determine what electrical accessories require additional field wiring,
refer to the unit specific wiring diagram located on the inside of the
unit control center access door . The low voltage control circuit is
24 Vac and control wiring should not exceed 0 .75 ohms . Refer to
Field Control Wiring Length/Gauge table for wire length maximums
for a given wire gauge . Control wires should not be run inside the
same conduit as that carrying the supply power . Make sure that field supplied conduit does not interfere with
access panel operation .

Field Control Wiring Length/Gauge

Total Wire Length

Minimum Wire Gauge

125 ft .

200 ft .

300 ft .

450 ft .