Mitsubishi Electric PQHY-P72ZLMU-A Service Handbook page 303

[ IX Troubleshooting ]
1. Error Code
6846
Start-up time over
2. Error definition and error detection method
Start-up time over The unit cannot finish start-up process within 4 minutes after power on.
3. Cause, check method and remedy
(1) Contact failure of indoor/heat source unit connecting wire
(2) Diameter or length of indoor/heat source unit connecting wire is
out of specified capacity.
(3) 2 or more heat source units have refrigerant address "0". (In case
of group control)
(4) Noise has entered into power supply or indoor/heat source unit
connecting wire.
HWE15150
Cause
- 294 -
Check method and remedy
Check disconnection or looseness or polarity
of indoor/heat source unit connecting wire of
indoor and heat source units.
Check diameter and length of indoor/heat
source unit connecting wire. Total wiring
length: 80 m (including wiring connecting
each indoor unit and between indoor and
heat source unit) Also check if the connec-
tion order of flat cable is S1, S2, S3.
Check if refrigerant addresses are overlap-
ping in case of group control system.
Check transmission path, and remove the
cause.
Note: The descriptions above, 1)-4), are for
EA, Eb and EC.
*The check code in the parenthesis indicates
PAR-30MAA model.
GB