11. Wiring
11.1. Caution
1 Follow ordinance of your governmental organization for technical standard
related to electrical equipment, wiring regulations and guidance of each
electric power company.
2
[2 in] or more apart from power source wiring so that it is not affected by
electric noise from power source wiring (Do not insert transmission line and
3 Provide designated grounding work to the heat source unit.
4 Include some allowance to wiring for the electrical control box on the indoor
and heat source units, because these boxes are sometimes removed at the
time of service work.
5 Never connect the main power source to the terminal block of the
transmission line. If connected, electrical parts will be damaged.
11.2. Control box and connecting position
of wiring
1 Heat source unit
1. Remove the front panel of the heat source unit by unscrewing the screws,
and pushing it up, then pulling it out.
2. Connect the indoor - heat source transmission line to the terminal block
If multiple heat source units are connected in the same refrigerant system,
daisy-chain TB3 (M1, M2,
the indoor - heat source transmission line to TB3 (M1, M2,
only one of the heat source units.
3. Connect the transmission lines for centralized control (between the
centralized control system and the heat source unit of different refrigerant
heat source units are connected to the same refrigerant system, daisy-chain
*1: If TB7 on the heat source unit in the same refrigerant system is not
daisy-chained, connect the transmission line for centralized control to
is being conducted during the power supply shut-off, daisy-chain TB7
on the OC and OS (In the case that the heat source unit whose power
supply connector CN41 on the control board has been replaced with
CN40 is out of order or the power is shut-off, centralized control will not
*2: OC and OS of the heat source units in the same refrigerant system are
order of capacity (If the capacity is the same, they will be in ascending
4. The indoor-heat source transmission line, connect the shield ground to the
grounding terminal (
whose power supply connector CN41 is replaced with CN40, short circuit the
5. Attach the connected wires securely with the cable strap at the bottom of the
terminal block. External force applied to the terminal block may damage it,
Caution:
- Poor wire contact caused by loose screws may result in overheating and
- The use of the unit with a damaged circuit board may result in overheating and
Note:
Make sure that the spring washers are parallel to the terminal block.
Make sure that the wires are securely fastened to the terminal screws.
Drive the screws straight down, and use caution not to damage the
screw heads.
Install the ring terminals back to back so that the screws can be driven
straight down.
Make an alignment mark with a permanent marker across the screw
head, washer, and terminal after tightening the screws.
34
6 Use 2-core shield cable for the transmission line. If transmission lines of
different systems are wired with the same multiplecore cable, the resultant
poor transmitting and receiving will cause erroneous operations.
7
block for heat source unit transmission.
The system will not operate with improper connection.
8 In the case of connecting a system controller or to conducting group
operation in different refrigerant systems, a transmission line is required
between the heat source units in different refrigerant systems.
Connect the transmission between the terminal blocks for centralized control
9 Use the remote controller to set the groups.
[Fig. 11.2.1] (P.15)
A Power source
C Ground terminal
[Fig. 11.2.2] (P.15)
A Terminal block with loose screws
C Spring washers must be parallel to the terminal block.
[Fig. 11.2.3] (P.15)
A Power wires, transmission lines
C
E Install the ring terminals back to back.
[Fig. 11.2.4] (P.15)
A Cable strap
C
2 Conduit tube installation
Hammer the knockout holes for the conduit tube located on the base and the
bottom part of the front panel.
When installing the conduit tube directly through the knockout holes, remove
burrs and protect the tube with masking tape.
Use the conduit tube to narrow the opening if there is a possibility of small
animals entering the unit.
11.3. Wiring transmission cables
1 Types of control cables
1. Wiring transmission cables
Types of transmission cables: Shielding wire CVVS, CPEVS or MVVS
Cable diameter: More than 1.25 mm
Maximum wiring length: Within 200 m [656 ft]
Maximum length of transmission lines for centralized control and indoor/heat
source transmission lines: 500 m [1640 ft] at the maximum
The maximum length of wiring between power supply unit for transmission
is 200 m [656 ft].
2. Remote control cables
ME Remote Controller
Sheathed 2-core cable
Type of remote control cable
0.3 to 1.25 mm
Cable diameter
(0.75 to 1.25 mm
When 10 m [32 ft] is exceeded, use cable
Remarks
transmission cables.
*
Connected with simple remote controller.
CVVS, MVVS: PVC insulated PVC jacketed shielded control cable
CPEVS: PE insulated PVC jacketed shielded communication cable
CVV: PVC insulated PVC sheathed control cable
MA Remote Controller
Type of remote control cable
0.3 to 1.25 mm
Cable diameter
(0.75 to 1.25 mm
Remarks
Within 200 m [656 ft]
*
Connected with simple remote controller.
B Transmission line
B Properly installed terminal block
B
D Make an alignment mark.
B Power source cable
2
[AWG 16]
2
[AWG 22 to 16]
2
2
[AWG 22 to 16]
2