Lennox MPB012S4S

131
Error Code: E3
Description: Indoor fan speed error.
General Note: Whenindoorfanspeedrunstoolow(300RPM)foracertaintime,theunitwillstopandtheLEDwilldisplaytheerror.
Indoor fan speed error
Poweroff,thenrestarttheunit2minutes
later.Doeserrorstilldisplay?
No
Shutoffpowersupplyandrotatefanby
hand.Doesfanspinfreely?
Yes
Theunitoperates
normally.
Checkthewiringofthefanmotor.Isit
connectedcorrectly?
Yes
Measurethevoltageforthefanmotor
fromthemainPCB.Isthevoltagecor-
rect?
Yes
Replacetheelectriccontrolbox.
Yes
No
Removeobstruction.
No
Correctthe
connections.
No
ReplacethemainPCB
Yes
Replacethefanmotor
No
1. Indoor DC fan motor (Control Chip is in Fan
Motor)
2. Turnpoweronandwhiletheunitisonstandby,
measure the voltage between pin1 and pin3
as well as between pin4 and pin3 in fan motor
connector.Ifthevalueofthevoltageisnotwithin
therangeshowninthefollowingtable,thePCB
may be experiencing problems and need to be
replaced.
DCMotorVoltageInputandOutput
NO. Color Signal Voltage
1 Red Vs/Vm 200~380V
2 --- --- ---
3 Black GND 0V
4 White Vcc 13.5~16.5V
5 Yellow Vsp 0~6.5V
6 Blue FG 13.5~16.5V