Wmf U1.4 To L2Ef Conversion - McQuay MWM Service Manual

MCQUAY Service Guide Book

6.4 WMF U1.4 to L2EF Conversion

1. The U1.4 PCB can be replaced directly by the
new L2EF PCB because no modification
needs to be done and the connector pins for
both stepper motor and fan motor is still the
same as U1.4.
2. However, the display panel (IR receiver) and
On/Off switch board pins on PCB for both U1.4
and L2EF is not compatible with each other;
therefore it is unable to change
Display
Panel
Display Panel
L2EF PCB: Comes with display panel and ON/OFF switch board
3. only the display panel or On/Off switch board
from U1.4 to L2EF or L2EF to U1.4.
4. For example, if the display panel for U1.4 is
malfunction, it cannot be replaced by the
display panel from L2EF as the connector pins
is already different.
Please refer to the following pictures for a clear
description of connector pins.
U1.4 PCB
ON/ OFF switch
board
38
Controller Configuration
ON/ OFF
switch board