En-8
7.2. Electrical requirement
Voltage rating
208/230 V
Operating range
187 to 253 V
• Select the power cable type and size in accordance with relevant local and national
regulations.
• Speci
fi
cations for local wiring power cord and branch wiring are in compliance with
local code.
• Select the correct cable type and size according to the country or region’s regulations.
• Max. wire length: Set a length so that the voltage drop is less than 2%. Increase the
wire diameter when the wire length is long.
Breaker should be installed at every refrigerant system. Do not use a breaker in a
different refrigerant system.
Refer to the table for the breaker speci
fi
cations of each installation condition. Perform the
power crossover wiring within the range of the same refrigerant system. When the crossover
wiring is done, make a connection for RB units to satisfy conditions A and B below.
A. Current breaker requirements
Model
MCA
MAX. CKT. BKR (Fuse capacity)
UTP-RU01AH
0.25 A
15 A
UTP-RU01BH
0.25 A
UTP-RU01CH
0.38 A
MCA: Minimum Circuit Ampacity
MAX. CKT. BKR : Maximum Circuit Breaker
When the power crossover wiring is done, make it so that the total of the MCA of the
connected RB units and indoor units does not exceed the 11 A. For indoor unit MCA,
refer to the indoor unit installation manual.
If the capacity of connected RB units and indoor units exceeds the upper limit, either
add breakers or use a breaker with a greater capacity.
B. Ground Fault Equipment Breaker requirements
Breaker capacity
Connectable RB units and indoor units
30 mA, 0.1 sec or less
36 or less *
100 mA, 0.1 sec or less
37 to 121
* If the total number of units connected to the breaker exceeds 36, either add a 30mA
breaker, or use breakers with a greater capacity.
7.2.1. Cable speci
fi
cations
Follow the speci
fi
cations below for the power supply and transmission cable.
Recommended
cable size (mm
2
)
Cable type
Remark
Transmission
cable
22 AWG
(0.33 mm²)
LONWORKS
compatible cable
22 AWG LEVEL 4 (NEMA)
non-polar 2 core, twisted
pair solid core diameter
0.026 in (0.65 mm)
7.3. Wiring
• Before attaching the cable to terminal block.
7.3.1. Power supply cable
Conduit connector
Earth (ground) wire
4-5/16 in (110 mm)
4-15/16 in (125 mm)
A. For solid core wiring
(1) To connect the electrical terminal, follow the below diagram and connect after
looping it around the end of the cable.
(2) Use the speci
fi
ed cables, connect them securely, and fasten them so that there is
no stress placed on the terminals.
(3) Use an appropriate screwdriver to tighten the terminal screws.
Do not use a screwdriver that is too small, otherwise, the screw heads may be
damaged and prevent the screws from being properly tightened.
(4) Do not tighten the terminal screws too much, otherwise, the screws may break.
(5) See the table for the terminal screw tightening torques.
(6) Please do not
fi
x 2 power supply cables with 1 screw.
Strip 1 in
(25 mm)
Screw with
special washer
Screw with
special washer
Cable end (Loop)
Cable end (Loop)
Terminal block
Cable
Loop
Cable
Do not apply branch wiring. It may result electric shock or
fi
re.
WARNING
When using solid core cables, do not use the ring terminal. If you use the solid
core cables with the ring terminal, the ring terminal's pressure bonding may
malfunction and cause the cables to abnormally heat up.
B. For strand wiring
(1) Use ring terminals with insulating sleeves as shown in the
fi
gure below to connect
to the terminal block.
(2) Securely clamp the ring terminals to the cables using an appropriate tool so that
the cables do not come loose.
(3) Use the speci
fi
ed cables, connect them securely, and fasten them so that there is
no stress placed on the terminals.
(4) Use an appropriate screwdriver to tighten the terminal screws.
Do not use a screwdriver that is too small, otherwise, the screw heads may be
damaged and prevent the screws from being properly tightened.
(5) Do not tighten the terminal screws too much, otherwise, the screws may break.
(6) See the table for the terminal screw tightening torques.
(7) Please do not
fi
x 2 power supply cables with 1 screw.
Screw with
special washer
Screw with
special washer
Terminal block
Cable
Cable
Ring terminal
Ring terminal
Sleeve
Strip 3/8 in
(10 mm)
Ring terminal
WARNING
Use ring terminals and tighten the terminal screws to the specified torques,
otherwise, abnormal overheating may be produced and possibly cause heavy
damage inside the unit.
Tightening torque
M4 screw
(Power supply / L1, L2 (N), GND)
11 to 16 lbf·in
(1.2 to 1.8 N·m)
7.3.2. Transmission cable
Shielded wire
(no
fi
lm)
1-9/16 in (40 mm)
1-3/16 in (30 mm)
• When the 2 cables are attached:
GOOD
PROHIBITED
Different diameter
Connect to 1 side
WARNING
Tighten the terminal screws to the specified torques, otherwise, abnormal
overheating may be produced and possibly cause heavy damage inside the unit.
Tightening torque
M3 screw
(Transmission / X1, X2)
4 to 5 lbf·in
(0.5 to 0.6 N·m)
CAUTION
To peel the
fi
lm from the lead cable, use a dedicated tool that will not damage the
conductor cable.
When installing a screw on the terminal block, do not cut the cable by
overtightening the screw. On the other hand, an under tightened screw can cause
faulty contact, which will lead to a communication failure.
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2015/2/26 13:11:33
