Mitsubishi Electric City Multi PUMY-P250YBM Installation Manual page 23

6. Electrical work
Warning:
• Be sure to use specified wires to connect so that no external force is imparted to terminal connections. If connections are not fixed firmly, it may cause
heating or fire.
• Be sure to use the appropriate type of overcurrent protection switch. Note that generated overcurrent may include some amount of direct current.
• Be sure to attach the terminal block covers/panel of the outdoor unit securely.
If it is not attached correctly, if could result in a fire or an electric shock due to dust, water. etc.
Caution:
• Be careful not to make mis-wiring.
• Firmly tighten the terminal screws to prevent them from loosening.
• After tightening, pull the wires lightly to confirm that they not move.
• If the connecting wire is incorrectly connected to the terminal block, the unit does not operate normally.
• Some installation site may require attachment of an earth leakage breaker. If no earth leakage breaker is installed, it
may cause an electric shock.
• Do not use anything other than breaker and fuse with correct capacity. Using fuse and wire or copper wire with too
large capacity may cause a malfunction of unit or fire.
• Properly route wiring so as not to contact the sheet metal edge or a screw tip.
IMPORTANT
Make sure that the current leakage breaker is one compatible with higher harmonics.
Always use a current leakage breaker that is compatible with higher harmonics as this unit is equipped with an inverter.
The use of an inadequate breaker can cause the incorrect operation of inverter.
Never splice the power cable or the indoor-outdoor connection cable, otherwise it may result in a smoke, a fire or communication failure.
Warning:
• Please turn off the main power supply when servicing. And do not touch the B1, B2 terminals when the power is energized. If isolator should be used be-
tween outdoor unit and branch box/indoor unit and branch box, please use 2-pole type. (Please refer to figure below.)
Caution:
After using the isolator, be sure to turn off and on the main power supply to reset the system. Otherwise, the outdoor unit may not be able to detect the
branch box(es) or indoor units.
Be sure to connect the outdoor-branch box/indoor-branch box connecting cables directly to the units (no intermediate connections).
Intermediate connections can lead to communication errors if water enters the cables and causes insufficient insulation to ground or a poor electrical contact at the
intermediate connection point.
6.4. Wiring transmission cables
Types of control cables
1
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
2. M-NET Remote control cables
Types of remote control cables Shielding wire CVVS, CPEVS or MVVS
Cable diameter 0.5 to 1.25 mm²
When 10 m is exceeded, use cable with the same
Remarks
specifications as 1. Wiring transmission cable
3. MA Remote control cable
Type of remote control cable Sheathed 2 - core cable (unshielded) CVV
Cable diameter 0.3 to 1.25 mm² (0.75 to 1.25 mm²)*
Remarks Within 200 m
* Connected with simple remote controller.
2 poles isolator (Switch)
B1
Outdoor unit
B2
2
• Controller name, symbol and allowable number of controllers.
2
Note:
*1. The number of connectable units may be limited by some conditions such
Branch box
L
N
Connection restrictions
Name Symbol
Outdoor unit controller OC
CITY MULTI
M-IC
Indoor unit
series
controller
M series A-IC
Branch box BC
M-NET M-NET RC Maximum of 30 controllers for 1 OC *1
Remote
MA MA-RC
controller
Wireless WL-RC
as an indoor unit's capacity or each unit's equivalent power consumption.
Loosen terminal screw.
Terminal
block Lead wire
Connection details
Allowable number of controllers
–
1 to 30 units per 1 OC *1
2 to 12 units per 1 OC *1
0 to 3 units per 1 OC
Maximum of 2 per group
–
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