Toshiba MMU-P0121H Service Manual page 135

3-8-3. Emergency Operation When Outdoor Unit has Failed
In this air conditioner, backup operation can be set up to both inverter unit and fixed-speed unit when outdoor
unit has failed.
In a system in which two or more outdoor units are connected, perform the emergency operation for failure of
outdoor unit when alarm mode such as the following cases occurs.
(1) Fault of compressor (Short or when one compressor is not operating)
(2) Fault of pressure sensor (Pd, Ps)/fault of temp. sensor (TD1, TD2, TS, TE, TK1, TK2, TK3)
(3) Fault of refrigerating cycle parts, fan system parts, interface P.C. board, IPDU P.C. board, electric part
system, etc.
*
NOTE : Perform emergency operation for only one unit in 1 system.
3-8-3-1. Fault in fixed-speed unit
(Setup of emergency operation for terminal outdoor unit)
<Outline>
When a fixed-speed unit connected to the system fails, perform emergency process according to the following
work procedure firstly, and then perform emergency operation by the inverter unit and other fixed-speed units.
<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 fixed-speed 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 pipes. ( : It is not provided in the cooling only model.)
(Fully close by complete turning clockwise)
3) Check service valve of the balancing pipe is open fully. (Fully open by turning counterclockwise)
4) [In case of fault of compressor/fault of electric part system]
a. Works to the failed fixed-speed unit are complete.
b. Then, keep the power supply OFF.
5) [In case of fault of other cycle part system]
a. Remove BUS-1 communication connector (BLU)[CN601] on the interface P.C. board.
b. Works to the failed fixed-speed unit are complete.
c. Then, turn on the power supply to protect the compressor. (Turn on crank case heater.)
(3) Perform the following works for the inverter unit.
1) Set DIP SW 07/Bit 3 on the interface P.C. board to ON. (Set up to correct oil recovery capacity)
2) Set DIP SW 09/Bit 2 on the interface P.C. board to ON. (Set up to not to detect indoor over capacity)
3) Turn on the power supply of each outdoor unit.
4) Set operation permission of outdoor unit backup operation. (Alarm clear set up)
a. Set rotary switches on the interface P.C. board, SW03 to [No.1]/SW02 to [No.1]/SW01 to [No.1].
b. After [U.][1][8][d] were displayed on the 7 segment LED of the interface P.C. board, set SW03 to
[No.1]/SW02 to [No.16]/SW01 to [No.2].
c. After [E.][r][ ][ ] are displayed on the 7 segment LED of the interface P.C. board, keep push-switch
SW04 pushed for 5 seconds or more.
[E.][r][C][L] are displayed on the 7 segment LED for 5 seconds, and work is complete.
d. Set SW03 to [No.1]/SW02 to [No.1]/SW01 to [No.1].
If [U.][1][ ][ ]are displayed on the 7 segment LED, it is normal.
(4) Then, emergency process is complete. The operation then starts by a command from the indoor unit.
*
, PMV B close service valve of the
3-132