JOHNSON CONTROLS
220
FORM 201.23-NM2
ISSUE DATE: 3/9/2015
SECTION 7 - OPERATION
TABLE 10 -
VSD BASEPLATE TEMPERATURE
LOAD LIMITING/UNLOADING
VSD BASEPLATE TEMPERATURE
UN-LOADING
Baseplate Temp. is between
Cutout- 8ºF & Cutout- 4ºF
0 Hz
Baseplate Temp. Cutout- 3.6ºF
1 Hz
Baseplate Temp. Cutout- 3.2ºF
2 Hz
Baseplate Temp. Cutout- 2.8ºF
3 Hz
Baseplate Temp. Cutout- 2.4ºF
4 Hz
Baseplate Temp. Cutout- 2.0ºF
5 Hz
Baseplate Temp. Cutout- 1.6ºF
6 Hz
Baseplate Temp. Cutout- 1.2ºF
7 Hz
Baseplate Temp. Cutout- 0.8ºF
8 Hz
Baseplate Temp. Cutout- 0.4ºF
9 Hz
Baseplate Temp. Cutout
10 Hz
FLASH TANK DRAIN AND FEED VALVE
CONTROLLER
Valve Controller and Control Algorithm
Operation
The Flash Tank Feed and Drain Valve PI Controller(s)
plays a dual role of supplying drive signals to control
the opening and closing of both the Flash Tank Feed
and Drain Valves. These valves control the liquid level
in the flash tank and the suction superheat of the com-
pressor. The Flash Tank Feed and Drain Valve Con-
troller receive analog signals from the Chiller Control
Board to position the Feed and Drain Valves.
The Chiller Control Board PI (Proportional plus In-
tegral) control algorithm in the Chiller Control Board
software determines the open % for the Drain and Feed
valves. A D/A converter on the Chiller Control Board
converts the 0-110.0% signal to an output voltage be-
tween 0VDC and 10.28VDC and sends it to the Drain
and Feed Controller. This voltage is then converted to
a valve position by the Drain and Feed Valve Control-
ler and a 2 phase (4 wire), signal drives the Feed Valve
open or closed. Power for the Valve Controller comes
from a 30VDC supply from the Chiller Control Board.
FIGURE 53 -
FLASH TANK DRAIN AND FEED VALVE CONTROLLER
LD10619
Summary of Contents for YCIV0157
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