External Auto-Stop - Trane CVHE Troubleshooting Manual

The following graph shows External Chilled Water Setpoint with a 2-10 VDC input:
70.00
60.00
50.00
40.00
30.00
20.00
10.00
0.00
-10.00
-20.00
2 2.5 3
The following items need to be set:
1 SW3-1 OFF for 2-10 VDC, ON for 4-20 mA.
2 Chilled Water Reset type: Disable - Operator Settings Group
3 Chilled Water Setpoint Source: External - Operator Settings Group
4 Setpoint Source Override: None - Operator Settings Group
5 External Chilled Water Setpoint: Installed - Service Settings Group Machine Configuration
6 In Machine Configuration, set to 4-20 mA or 2-10 VDC; 4-20 is default
7 Grounding of the BAS and UCP2 systems may be different. To clear this, connect a 9 VDC
battery to J9 (4, 8). This acts as an isolated source and you should read 9 VDC. If you do not
read 9 VDC, a grounding problem exists.

External Auto-Stop:

The external Auto-Stop input allows the operator to enable and disable chiller operation through
a remotely located set of contacts.
A binary input to the UCP2 is provided that will enable the chiller to operate when it is closed and
disable operation when it is open. An indication is displayed on the front panel when the chiller is
disabled through the remote Auto-Stop.
The Auto-Stop input allows the operator to use a remote signal, such as a time clock or a generic
BAS, to signal the start of the chiller. Disabling the chiller through this input will not result in a
diagnostic since it is an expected routine shutdown.
CVHE-SB-32A
External Chilled Water Setpoint with VDC input
Degrees F
3.5 4 4.5 5 5.5 6
Volts DC
Degrees C
6.5 7 7.5 8 8.5 9
Degrees F
Degrees C
9.5 10
57