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Communication Cable Connection
Note:
When connecting the communications bus between the
outdoor unit and DOAS unit(s), it does not matter what
physical path or route the wire takes. The installer may use
discretion when choosing the order the components are
connected to the communications bus, but must maintain the
daisy chain and polarity configuration.
1. Access hole of Communication and power cable are
located at the bottom of Unit. Remember the
communications cable and the power cable must
enter the control box through different knockouts.
2. Rubber grommet in the knockout hole to prevent wire
chaffing.
3. If using conduit, connect the conduit to the control box
using field-provided fittings and industry best-practice
procedures.
4. Provide at least three (3) to four (4) inches of slack
cable at each Compact DOAS unit.
5. Secure the communications cable to the inside
surface of the control box using a field provided nylon
wire clamp.
6. Strip approximately quarter of an inch of insulation
from each communications cable conductor. At each
DOAS unit, insert the conductors under the terminal
screw.
7. Securely tighten the terminal screws to prevent the
communications conductors from coming loose from
the terminal block
8.
Secure the communications cable in appropriate
locations outside the indoor unit to prevent damage to
the cable or injury to maintenance personnel
.
Connecting the Power Wiring
High voltage electricity is required to operate this
system. Adhere to the National Electrical Codes and
these instructions when wiring. Always ground the
unit following local, state, and National Electrical
Codes. Read the safety summary at the beginning of
this manual.
•
Secure all field wiring connections with appropriate wire
strain relief. Improperly securing wires will create undue
stress on equipment power lugs. Inadequate connections
will generate heat, cause a fire and physical injury or death.
•
Properly tighten all power connections. Loose wiring will
overheat at connection points, causing a fire, physical injury
or death.
Note:
•
Connect the DOAS unit input power cable but
apply power to the DOAS unit until authorized to do so by
the system commissioning agent. Inappropriate power
connection can result in equipment damage and will void
the LG limited liability warranty.
•
When connecting the communications bus between the
outdoor unit and DOAS unit(s), it does not matter what
physical path or route the wire takes. The installer can use
discretion when choosing the order the components are
connected to the communications bus, but must maintain
the daisy chain and polarity configuration.
•
Failure to follow any of these power and communications
wiring guidelines or instructions will cause communications
errors and unit malfunction.
Don’ts
Never use wire caps and never splice communications
cables.
•
Never connect central controllers or LG building
management system gateways to the DOAS unit / outdoor
unit communications cable.
Connection Procedure
DOAS unit installation best practices are to connect
control wiring (low voltage) and then connect power
wiring (high voltage). Do not apply power to the DOAS
unit or any Multi V system component until authorized to
do so by the system commissioning agent.
1. Ensure the input power is disconnected and there is
no power on the power input cable.
2. Remove the knockout plugs from the control box.
Remember the communications cable and the power
cable must enter the control box through different
knockouts.
3. Install a field provided plastic or rubber grommet in the
knockout holes to prevent wire chaffing.
4. If using conduit, connect the conduit to the control box
using field provided fittings and industry best-practice
procedures.
5. Ensure the power wiring is routed separately from the
communications cable to the unit’s terminal block
(see figure17).
cable near the power cable. Provide at least three (3)
to four (4) inches of slack cable at each DOAS unit.
Note:
Power wiring is field supplied. Wire size is selected based on
the larger MCA value, and must comply with the applicable
local and national codes.
6. Connect the power wiring to the terminal block
connections. Ensure the screws securely connect the
wire to the terminals and are not loose.
7.
Polarity matters on the outdoor unit to DOAS unit
communications bus, and must be maintained
throughout the entire system. Be sure to connect:
•
IDU-A terminals (outdoor unit) to ODU(IDU)-A (DOAS unit)
terminals and connect IDU-B terminals (outdoor unit)
terminals to ODU(IDU)-B (DOAS unit) terminals.
•
Central-A terminals (outdoor unit) to ODU(CEN)-A (DOAS
unit) terminals and connect Central-B terminals (outdoor
unit) to ODU(CEN)-B (DOAS unit) terminals.
Refer to the preceeding pages for DOAS unit wiring
connections.
do not
Do not route the communications
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