Toshiba MMU-P0121H Service Manual page 136

3-8-3-2. Fault of inverter unit
(Setup of emergency operation for center outdoor unit)
<Outline>
When an inverter unit fails, perform emergency process according to the following work procedure firstly, and
then perform emergency operation by other fixed-speed unit only.
<Work procedure>
(1) First, turn off the power supply of all the outdoor units which are connected to the system.
(2) The following works are performed to the failed inverter unit.
1) Close service valve of gas pipe fully. (Fully close by turning clockwise)
2) If refrigerant leakage (Not closed) occurs on even one of PMV A
liquid pipe fully. (Fully close by turning clockwise) (
3) Check service valve of the balancing pipe is opened fully.
(Fully open by turning counterclockwise)
4) Remove <Short-circuit connector> connected to [CN604] on the interface P.C. board. The removed
<Short-circuit connector> is used for the fixed-speed unit. (Described in item (4) below.)
5) [In case of fault of compressor/fault of electric part system]
a. Works to the failed inverter unit is complete.
b. Then, keep the power supply OFF.
c. When central management remote controller is connected to the inverter unit, the central manage-
ment remote controller cannot be used.
6) [In case of fault of other cycle part system]
a. Set DIP SW06/Bit 1, 2, 3, 4 on the interface P.C. board to ON. (LED display changes to
b. Works to the failed inverter unit is complete.
c. Then, turn on the power supply to protect the compressor. (Turn on winding heater)
d. The central management remote controller is used normally.
(3) Select a master outdoor unit among the fixed-speed units according to the following reference.
1) When only one fixed-speed unit is connected, select it as the master outdoor unit.
2) When two or more fixed-speed units are connected, select one connected to the nearest position of the
inverter unit as the master outdoor unit.
(4) Perform the following works for the fixed-speed unit selected as the master outdoor unit.
1) Insert <Short-circuit connector> into [CN604] on the interface P.C. board.
(One removed from the inverter unit)
2) Set DIP SW07/Bit 3 on the interface P.C. board to ON. (Set up to correct oil recovery capacity)
3) Set DIP SW08/Bit 2 on the interface P.C. board to ON. (Set up to select center outdoor unit)
4) Set DIP SW09/Bit 2 on the interface P.C. board to ON. (Set up not to detect indoor over capacity)
(5) Turn on the power supply of each outdoor unit.
(6) Emergency process is complete. The operation then starts by a command from the indoor unit.
*
, PMV B close the service valve of the
*
: It is not provided in the cooling only model.)
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