Electrical Work; Caution - Mitsubishi Electric City Multi Y Série Manuel D'installation

11. Electrical work

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.
Warning:
Be sure to have authorized electric engineers do electric work using special circuits in accordance with regulations and this installation
manual. If power supply circuit has a lack of capacity or electric work deficiency, if may cause an electric shock or fire.
2 Install the outdoor unit transmission line away from the power source wiring so that it is not affected by electric noise from the power source. (Do not
run it through the same conduit.)
3 Be sure to provide designated grounding work to outdoor unit.
Caution:
Be sure to put outdoor unit to earth. Do not connect earth line to any gas pipe, water pipe, lightning rod or telephone earth line. If earth is
incomplete, it may cause an electric shock.
4 Give some allowance to wiring for electrical part box of indoor and outdoor units, because the box is sometimes removed at the time of service work.
5 Never connect the main power source to terminal block of transmission line. If connected, electrical parts will be burnt out ( mark in the figure
below).
6 Use 2-core shield cable for 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 Only the transmission line specified should be connected to the terminal block for outdoor unit transmission.
(Transmission line to be connected with indoor unit : Terminal block TB3 for transmission line, Other : Terminal block TB7 for centralized control)
Erroneous connection does not allow the system to operate.
8 In case to connect with the upper class controller or to conduct group operation in different refrigerant systems, the control line for transmission is
required between the outdoor units each other.
Connect this control line between the terminal blocks for centralized control. (2-wire line with no polarity)
When conducting group operation in different refrigerant systems without connecting to the upper class controller, replace the insertion of the short
circuit connector from CN41 of one outdoor unit to CN40.
9 Group is set by operating the remote controller.
TB3: Transmission line terminal board, TB7: Central control line terminal board
A Outdoor unit
B 2-core cable
C Indoor unit
D Remote controller
E Multi-core cable
×
mark in the figure below).
A
C
TB3
B
TB7
D
TB3
B
TB7
A
C
TB3
E
TB7
D
TB3
TB7
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