Stop Operation; Startup Control - Trane TVR Pro CO Series Service Manual

2 Stop Operation

The stop operation occurs for one of the three following reasons:
1. Abnormal shutdown: in order to protect the compressors, if an abnormal state occurs the system makes a 'stop with
thermo off' operation and an error code is displayed on the outdoor unit digital displays.
2. The system stops when the set temperature has been reached.
3. A unit stops when the load demanded by the indoor units decreases and can be handled by fewer outdoor units.

3 Startup Control

3.1 Compressor Startup Delay Control
In initial startup control, compressor startup is delayed for 12 minutes in order to let the master unit search for the indoor
units' addresses. In restart control (except in oil return operation), compressor startup is delayed such that a minimum of 7
minutes has elapsed since the compressor stopped, in order to prevent frequent compressor on/off and to equalize the
pressure within the refrigerant system.
3.2 Startup Control for Cooling Operation
Table 3-3.1: Component control during startup in cooling mode
Component
Inverter compressor A
Inverter compressor B
DC fan motor A
DC fan motor B
Electronic expansion
valve A
Solenoid valve (Liquid
injection)
Solenoid valve (oil
balance)
Solenoid valve
(refrigerant bypass)
Wiring diagram
8-12HP
label
BP1
●
BP2
FAN1
●
FAN2
EXVA
●
SV2
●
SV4
●
SV7
●
14-16HP 18-22HP 24-30HP
● ● ●
● ●
● ● ●
● ●
● ● ●
● ● ●
● ● ●
● ● ●
25
Control functions and states
Controlled according to
operating frequency increased by 1 step / sec
Fan speed controlled according to discharge
pressure (P ):
c
At initial speed for 90 seconds.

Subsequently, P checked every 10 seconds:

c
P ≥ 2.7MPa => 1 step increase.

c
P ≤ 2.1MPa => 1 step decrease.

c
Position (steps) from 0 (fully closed) to 3000 (fully
open), controlled according
temperature
Controlled according to discharge temperature
Closed for 200 secs, open for 600 secs, then
closed
Controlled according to load requirement and
discharge pressure
load requirement,
to discharge