Wiring Connection Between Mds Outdoor Units - McQuay MDS Series Service Manual

For the last indoor unit, the communication jumper needs to be shorted. This is to indicate to the outdoor unit that
this is the last indoor unit. If the jumper is not shorted, the communication between the outdoor and indoor is not
stable. It may cause the outdoor model to trip after some time of operation. The communication jumper is labeled
with the name JP1 and the location is shown below.
3
Location of jumper JP1 on indoor PCB MC200-C (left) and MC201-C (right)

3.3.2 Wiring Connection Between MDS Outdoor Units

When more than one outdoor is to be connected together within a system, the wiring connection is connected as
shown in the figure above. For MDS-M PCB, the jumper JP6 of the last outdoor unit within the system needs to
be shorted (refer to figure below). This is to indicate to the software that this will be the last outdoor unit.
Short jumper JP6
20 Service Manual SM-MDS_(ii)