Johnson Controls YORK YVAM - Testing Evaporator Shell Heaters EVH1 and EVH2; Testing Heat Trace for Drive Coolant HT1 and HT2; Testing the VGD Actuator Heater Mat; Testing the MBC Heater Mat

2. At the auxiliary power panel, use wires 325 and 325 A to measure the current to the heaters.
The nominal current for each one is 3.75 A. However, it may read lower values based on the
load at the time of testing.
3. Return the J9 connector immediately after recording the current value. Record the value in
160.88-CL2.
Testing heat trace for drive coolant HT1 and HT2
The heat trace for VSD coolant HT1 and HT2 is powered by the customer by the HTR DIST enclosure.
1. Unplug the ambient temperature sensor to the OptiView by removing the J9 plug from the
microboard to energize the heater.
2. At the HTR DIST panel, use wires 141 and 141A to measure the current to the heaters. The
nominal current for each one is 2 A. However, it may read lower values based on the load at
the time of testing.
3. Return the J9 connector immediately after recording the current value. Record the value in
160.88-CL2.
Testing the VGD actuator heater mat
1. Measure the current to the heater using either wire at the thermal switch, as shown in Figure
61. The nominal current is 1.5 A. However, it might read lower values based on the load at the
time of testing.
Figure 61: Heater mat temperature switch
2. Use an electronics safe freeze spray to lower the temperature of the metal portion of the
heater switch to energize the heater. The spray can be purchased at most supply houses. See
Figure 61 for the switch image.
3. Record the value in 160.88-CL2.
Testing the MBC heater mat
1. Measure the current to the heater using either wire at the thermal switch, as shown in Figure
61. The nominal current is 2.5 A. However, it might read lower values based on the load at the
time of testing.
2. Use an electronics safe freeze spray to lower the temperature of the metal portion of the
heater switch to energize the heater. The spray can be purchased at most supply houses. See
Figure 61 for the switch image.
3. Record the value in 160.88-CL2.
Testing the drive internal heater
1. Measure the current to the heater using wire 31 at 5BR on TB6 in the OptiView panel.
2. At the internal drive heater, raise the temperature control knob to a setting above ambient to
energize the heater. The nominal current is 7.3 A. However, it might read lower values based
on the load at the time of testing. See Figure 62.
YVAM with OptiView Control Center162