Enviro VB09-36, Установка, эксплуатация и обслуживание, Страница: 15 / 40

FORM ET145.18-IOM1 (115)
ENVIRO-TEC 15
4. ELECTRICAL WIRING
LOCK ALL ELECTRICAL POWER SUPPLY
SWITCHES IN THE OFF POSITION BEFORE
INSTALLING THE UNIT. FAILURE TO DIS-CONNECT
POWER SUPPLY MAY RESULT IN ELECTRICAL
SHOCK OR EVEN DEATH.
A. Field Installed Power Wiring
Power wiring to the equipment must conform to National and
Local Codes (NEC) by a professional electrician.
Provide each unit with its own separate electrical circuit,
means of circuit protection, and electrical disconnect switch.
Follow current National Electrical Code ANSI/NFPA 70, CSA
C22.1 C.E.C. Part 1, and state and local codes.
Failure to provide these shut-off means could cause
electrical shock or fire, resulting in damage, injury
or death.
Use Copper Conductors Only!
Verify that the available unit power supply is compatible with
the unit’s nameplate rating. Ensure breaker is properly sized
as per nameplate. Line voltage supply enters through the right
hand side of the cabinet at the 7/8” power entrance knock-out.
Connect to the line side of the factory installed terminal block.
Unit terminals are not designed to accept other types of
conductors. Failure to use copper conductors may result in
equipment damage.
B. Field Installed Low Voltage Wiring
Select a location for room thermostat that is away from supply
air registers, on draft-free interior wall, and not near lights,
television, direct sunlight, or other heat sources.
Thermostat connection within the unit is accomplished by
connecting the remote thermostat wiring to microprocessor low
voltage terminal strip. See Figure 4 for typical wiring
connections.
Locate thermostat away from supply drafts. Ensure
the back of thermostat is sealed and protected from
air drafts. Short cycling can result in damage to unit.
RECOMMENDED
WIRE SIZE
MAX. LOW VOLTAGE
WIRE LENGTH
20 gauge 50 feet
18 gauge 75 feet
16 gauge 125 feet
FIGURE 4 – FIELD WIRING DIAGRAM
Ensure that the control wiring between the thermostat and the
unit’s terminations does not exceed 1 ohm.
Resistance in excess of 1 ohm may cause
component damage due to insufficient AC voltage
supply.
Check all loads and conductors for grounds, shorts,
or misfiring. Do not run the low voltage wiring in the
same conduit with the high voltage power wiring.
C. Optional Surface Mount Thermostat Connection Wiring
For applications where thermostat is mounted directly above
the return air panel, cabinet Control Option ‘P’ must be
selected (i.e. VB12
P ). Thermostat molex pigtail harness
(shipped loose to field) is field wired to thermostat terminals
and molex connector clips to mating panel mounted molex
connector on unit cabinet, located 7 inches above the electrical
box. See optional 24V surface mount connection in Figure 2.
D. Optional Remote Mounted Thermostat Wiring
For units ordered with extended thermostat harness option the
thermostat is remote mounted and specific extended harness
length can be ordered. Extended harness is plenum rated. Use
low voltage 7/8” knock-out on the side of the unit at the
electrical box to field wire the low voltage thermostat wiring.
Using a plastic bushing pass harness inside electrical box to
factory wired mating molex harness. See Figure 5 below.
Thermostat pigtail molex harness is shipped loose for field
wiring to thermostat terminals.