Daikin WGZ200DW - Condenser Fan Control

16 WGZ030D through WGZ200D OMM 1130-2
directions and the sequence of operation can be found on page 65. Some means of discharge pressure
control must be installed if the condenser water temperature can fall below 60°F (16°C).
Condenser Fan Control
Model AC chillers equipped with air-cooled or evaporative-cooled condensers usually require some form
of discharge pressure control. The MicroTech II controller can be programmed to provide this function
by cycling condenser fans based on the unit discharge pressure. Directions on the pressure settings can be
found on page 65. The following charts illustrate how four controller outputs can control six fan steps.
Circuit 1
Number of Fans = 4 Number of fans = 6 Number of fans = 8
Stage #
Fan
1
Fan
3
Stage #
Fan
1
Fan
3
Fan
5
Stage #
Fan
1
Fan
3
Fan
5
Fan
7
1
ON
1
ON
1
ON
2
ON
ON
2
ON
ON
2
ON
ON
3
ON
ON
ON
3
ON
ON
ON
4
ON
ON
ON
ON
Number of fans = 8 (R410A)Number of fans = 10 (R410A)Number of fans = 12
Stage #
Fan
1
Fan
3
Fan
5&7
Stage #
Fan
1
Fan
3
Fan
5&7
Fan
9
Stage #
Fan
1
Fan
3
Fan
5&7
Fan
9&11
1
ON
1
ON
1
ON
2
ON
ON
2
ON
ON
2
ON
ON
3
ON
ON
3
ON
ON
3
ON
ON
4
ON
ON
ON
4
ON
ON
ON
4
ON
ON
ON
5
ON
ON
ON
ON
5
ON
ON
ON
6
ON
ON
ON
ON
Circuit 2
Number of Fans = 4 Number of fans = 6 Number of fans = 8
Stage #
Fan
2
Fan
4
Stage #
Fan
2
Fan
4
Fan
6
Stage #
Fan
2
Fan
4
Fan
6
Fan
8
1
ON
1
ON
1
ON
2
ON
ON
2
ON
ON
2
ON
ON
3
ON
ON
ON
3
ON
ON
ON
4
ON
ON
ON
ON
Number of fans = 8 (R410A)Number of fans = 10 (R410A)Number of fans = 12
Stage #
Fan
2
Fan
4
Fan
6&8
Stage #
Fan
2
Fan
4
Fan
6&8
Fan
10
Stage #
Fan
2
Fan
4
Fan
6&8
Fan
10&12
1
ON
1
ON
1
ON
2
ON
ON
2
ON
ON
2
ON
ON
3
ON
ON
3
ON
ON
3
ON
ON
4
ON
ON
ON
4
ON
ON
ON
4
ON
ON
ON
5
ON
ON
ON
ON
5
ON
ON
ON
6
ON
ON
ON
ON
ICE
In ICE mode, the compressors stage to 100% load until the LWT is less than the ICE LWT SP. Then
Compressors #3 and #4 shut down. Following that, Compressors #1 and #2 shut down after going
through normal pumpdown on both circuits. There is a programmable, start-to-start, Ice Mode Start
Delay that limits the frequency of starts when in the ice mode. The timer can be manually cleared to
force a restart.