51
Figure 35 - Shows the jumper that is to be
removed (jumped between 9 and GS).
Note, the potentiometer is still active in the
electrical loop. Refer to Figure 34.
Figure 36 - Potentiometer
The potentiometer dial should be set for the
maximum fan speed for a particular
application.
Maximum
fan
speed
is
determined by the ECat submittal. Typically,
this max speed will be the rpm set at the
factory.
The fan speed can be modulated using the
0-10 VDC input signal.
To check fan output from the factory, the
potentiometer can be dialed to 100%. By
sending a 5V signal*, for instance, the rpm
can be measured and this reading can be
converted to cubic feet of air moved by the
fan.
It is advised that a medium range signal* be
utilized for this procedure. The highest
signal sent by the controller should then be
determined by adjustment.
Adjusting Refrigerant Charge
Adjusting the charge of a system in the field
must be based on determination of liquid sub-
cooling and evaporator superheat. On a
system with a TXV, liquid sub-cooling is
more representative of the charge than
evaporator superheat but both measurements
must be taken.
Before completing startup and leaving
the unit a complete operating cycle
should be observed to verify that all
components are functioning properly.
CAUTION
The Clean Air Act of 1990 bans the
intentional venting of refrigerant
(CFC’s and HCFC’s) as of July 1,
1992. Approved methods of recovery,
recycling or reclaiming must be
followed. Fines and/or incarceration
may be levied for non-compliance.
CAUTION