Toshiba MMY-MUP0721FT6P-UL Service Manual page 224

▼How to Check Resistance of Compressor Winding
(1) Turn off the power supply.
(2) Remove compressor leads from the compressor P.C. board. (Be sure to remove all the leads.)
(3) With each compressor, check the phase-to-phase winding resistances and winding-to-outdoor cabinet
resistance using a multimeter.
・Earth trouble?
→ It is normal if the winding-to-outdoor cabinet resistance is 10MΩ or more.
・Inter-winding short circuit?
<Target model：MMY-MUP****FT6*>
→ Normal resistance between phase to phase is below. (Use a mΩ multimeter)
・LA771A3TB-20M : 0.242 ± 5%
・LA1201K4FB-10UC : 0.204Ω ± 5%
<Target model：MMY-MUP****FT9*>
→ Normal resistance between terminal to terminal (T-T, S-S, R-R) is below. (Use a mΩ multimeter)
・NA772A3TB-21M：0.121 ± 5%
・NA1201K4FB-10UC：0.102 ± 5%
Compressor side terminal position
460V models (6~16ton)
White
Black
Red
Draw out the comp.
leads straight.
▼How to Check Resistance of Compressor Winding
(1) Turn off the power supply.
(2) Remove fan motor leads from the fan P.C. board for the outdoor fan.
(3) Rotate the fan by hand. If the fan does not turn, the fan motor is troubled (locked up). Replace the fan motor.
If the fan turns, measure the phase-to-phase winding resistances using a multimeter. It is normal if the
measurements are in range below. (Use a digital multimeter.)
・MMY-MUP****FT6*：9.3 – 11.5Ω
・MMY-MUP****FT9*：3.0 – 3.7Ω
208-230V
Standard 6~10ton
High heat 6ton
Black
Red
White
Draw out the comp.
leads straight.
208-230V
Standard 6~10ton
High heat 6ton
Black
White
Black
Red
White
- 224 -
Draw out the comp.
leads straight.
Red
Red
Black
White