Carrier 38VT 188CTST Series - Page 28

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◆ Reuse Existing Communication Wiring Flowchart
START
Is the communication wiring condition out of damage,
crack, deteriorate, etc?
Can the communication wiring be reused safely?
(Check whether the communication wiring line and
ground is connected or not)
NO
Unable to reuse the
exisiting communication
wiring.
Please change or renew
the communication
wiring.
※Do not use wiring that
has crack, damage,
deteriorate, etc as it may
cause electric shortage,
fire and malfunction.
YES
Did the outdoor unit with the exisiting communication
wiring before update operate normally without any
abnormalites, malfunction, failure, etc in the past 1 year
related to communication line?
NO
Are the abnormalities,
malfunction, failure, etc related
to communication line properly
repaired?
NO
YES YES
Did the outdoor unit with existing communication wiring
before update operate normally without having any
noise from other devices such as TV and Radio?
NO
Are the noise from other devices
such as TV and Radio properly
repaired?
NO
YES YES
Is the communication wiring and another wiring (power
supply wiring, ground wiring, etc) separated at least
50 mm or more without bundling each other?
NO
Is it possible to separated the
communication wiring and another
wiring by 50 mm or more?
NO
YES YES
Does the exisiting communication wiring meet the
wiring type, size and length specifications of the
updated outdoor unit? Please confirm the specification
by refer to table below and wiring diagram.
NO
Connecting wiring between
indoor and outdoor units (Uv Line)
Connecting wiring between
outdoors units (Uc Line)※1
Central Controller Wiring (Uh Line) Remote Controller Wiring
Wiring 2-core, Non-Polarity Wiring 2-core, Non-Polarity Wiring 2-core, Non-Polarity
Type Shield Wire Type Shield Wire Size/Length 0.5 to 2.0 mm
2
Size/Length 1.0 to 1.5 mm
2
: up to
1000 m
Size/Length 1.0 to 1.5 mm
2
: up to
1000 m
2.0 mm
2
: up to
2000 m
Length
• Up to 500 m
• Up to 400 m in case two remote
controller in group control
• Up to 200 m total length of
communication wiring between
indoor units
Please use the wire size as desribed in {~{ mm
2
within that range. Other than that, use the smallest size.
※1 • Connecting wiring length is total length of connecting wiring length between outdoor units and connecting wiring length between
indoor and outdoor units (The length is for the same refrigerant line. Each refrigerant line is independent for each other)
YES
Able to reuse exisiting
communication wiring
Note when reusing exisiting communication wiring
1. For communication wiring, please use vinyl cord or 2-core non polarity
wire.
When using multi-core wire with 3 or more cores, use only 2 cores,
bundle the other separetely and earthed only the one side as like the
shield wire
2 When using shied wire, earthed only the one side of the wire on the
outdoor unit.
3 Do not use wire smaller than 0.5 mm
2
or larger than 2.0 mm
2
.
Do not use wire that has crack, damage, deteriorate, etc as it may
cause electric shortage, fire and malfunction etc
Wiring Diagram
Please refer to diagram below when connecting the communication wiring.
A
B
A
B
A
B
A
B
A
B
U3 U4
Uh
U1 U2
Uv
A
B
U1 U2
Uv
A
B
U1 U2
Uv
SHIELD SHIELD
Uc Uc
vUvU
U
v
Uv Uh Uh
SHIELD SHIELD
Uc Uc
U
v
Uv Uh Uh
Header outdoor
Central control
device
Control wiring between outdoor units (Shield wire)
Control wiring between indoor and outdoor units (Shield wire)
Control wiring between indoor units (Shield wire)
tinu roodnItinu roodnI Indoor unit
Remote controller Remote controller Remote controller
(Group control)
Indoor unit
Follower outdoor
Note:
• Communication wiring and central control wiring use 2-core non-polarity wires.
Use 2-core shield wires to prevent noise trouble. In this case, ends of the communication wire must be grounded.
• Use 2-core non-polarity wire for remote control. (A, B terminals)
Use 2-core non-polarity wire for wiring of group control. (A, B terminals)