Mitsubishi Electric CITY MULTI CMB-P1010V-E, Service Handbook

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1 LEV
Note 1 :
• Symptoms of incorrect connection to BC controller LEV board
Improper installation is the same for 1 and 2 , so it is omitted here.
Note 2 : Method for checking LEV full open, full closed condition
1 Check LEV full opening (pulse) using the LED monitor display (outdoor controller board SW1).
Full opened: 2000 pulses
Full closed: 60 pulses (LEV 1 may be greater than 60 during full heating operation.)
2 With LEV full opened, check for pressure differential by measuring temperature of piping on both sides.
3 With LEV full closed, check for refrigerant noise.
Note 3 : Use the following table to determine opening due to LEV differential pressure control and superheat
control.
• BC controller LEV basic operation characteristics
Region Failure mode Operating mode Description Normal range
LEV No. 1 3 Cooling-only Cooling-main Heating-only Heating-main
1) 1 3 Normal
← ← ←
2) 3 1 Insufficient cooling
SH12 small,
SC11 small
SC16 small
Branch piping SC small Insufficient cooling, insuf-
ficient heating
SH12 small, SC11 small
SC16 large,
Branch piping SC small
PHM large
Heating indoor SC small
PHM large
Insufficient cooling
Heating indoor SC small
PHM large
Small
Large
Small
Large
High pressure (PS1) - medium pressure (PS3) is large.
High pressure (PS1) - medium pressure (PS3) is small.
SH12 is large.
High pressure (PS1) - mid pressure (PS3) is small.
SC16 and SH12 are small.
High pressure (PS1) - mid pressure (PS3) is large.
Heating-only
Heating-main
Cooling-main
Cooling-only
Cooling-main
Heating-only
Heating-main
Cooling-only
Cooling-main
Heating-only
Heating-main
2.0 ~ 3.5 kg/cm 2 G
(0.20~0.34MPa)
SH12<25
2.0 ~ 3.5 kg/cm 2 G
(0.20~0.34MPa)
SC16>6
SH12>5
2.0 ~ 3.5 kg/cm 2 G
(0.20~0.34MPa)
LEV1
pulse
LEV3
pulse