Toshiba MMU-P0121H Service Manual page 115

3-7-1-5. Display on remote controller
In the following conditions, "STANDBY" is displayed on the remote controller.
1) "STANDBY" display
Fan operation is available, but PMV of the indoor unit is not opened. (Refrigerant does not flow.)
a. Indoor unit capacity over
When the total horse power of the indoor units exceeds 1.35 times of outdoor horse power, the indoor
unit enters STANDBY status.
The check code "89" is displayed at the same time when "STANDBY" is displayed.
b. Outdoor unit phase order error
If phase order of power supply of the outdoor unit is different, the indoor unit enters STANDBY status.
The check code "AF" is displayed at the same time when "STANDBY" is displayed.
c. Outdoor heating priority
*
While the outdoor unit operates in HEAT mode, the indoor unit which was set to COOL mode enters
STANDBY status.
No check code is displayed though "STANDBY" is displayed.
d. Cooling only operation of outdoor unit
*
When the outdoor unit is set to COOLING only operation mode, the indoor unit which was set to
HEAT mode enters STANDBY status.
No check code is displayed though "STANDBY" is displayed.
e. Indoor operation below 0.8HP control
When the total horse power of the operating indoor units is below 0.8HP, the indoor unit which
operation is set up enters STANDBY status. "STANDBY" is displayed though the check code is not
displayed.
Check setting of SW08 on the indoor main P.C. board (MCC-1349).
2) "PRE HEAT, DEFROST" display
*
In this time, there is possibility to stop the fan operation.
a. Cold draft protective control (Hot start)
If the indoor heat exchanger is not sufficiently heated when heating operation has started (or
thermostat-ON), "PRE HEAT, DEFROST" is displayed.
After the heat exchanger has sufficiently heated, "PRE HEAT, DEFROST" display disappears and the
fan starts operation.
b. Heating refrigerant/Oil recovery control
When the outdoor unit starts heating refrigerant and oil recovery control, an indoor unit which enters
other mode than HEAT or of which heating thermostat is off stops operation of the fan and displays
"PRE HEAT, DEFROST".
On the indoor unit of which fan stops, "PRE HEAT, DEFROST" is not displayed.
*
( : The description is applied to the Heat Pump model only.)
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