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Page 36
GUARDIAN SCC-40
Issue (Auto VI) & V3.6t 07/12/00
CAPACITY PRESSURE LOW TRIP
=COMPRESSOR AUTO STOP
The % Slide position at which below setpoint the stagedown timer autostops the
compressor, restart is automatic after starts per hour
SH
timed out.
No Action If Set to Zero
SUCTION PRESSURE LOW ALARM/LOW TRIP
=STOP-COMPRESSOR
The minimum suction pressure for the compressor in increments of 0.1 bar.
This setpoint merely stops the compressor which automatically restarts again
when the suction pressure rises again without needing RESET to be pressed.
DISCHARGE PRESSURE SETPOINT
CONDENSER FANS 1 & 2
With VI relays selected for 'FANS' FAN-1 (VI-1) is switched on when the
discharge pressure is above this setpoint. FAN-2 (VI-2) is switched on
'Ft0.x'
bar above this setpoint. Both fans are switched off 0.5 bar below their respective
setpoints.
CONTROL MODES
GENERAL
The controller is a general purpose screw compressor controller. It may be used
as a stand-alone unit or may be integrated into an overall pack control strategy
via the communications link with upto 5 other units.
The control and monitoring operations are based on the inputs and outputs
described previously.
The controller has three modes of operation:-
i) MANUAL
Operator required to start/stop and control capacity.
ii) LOCAL AUTOMATIC
Compressor start/stops and controls capacity on suction pressure, equivalent
temperature or chiller temperature setpoint control provided refrigeration input
signal is enabled.
iii) REMOTE AUTOMATIC
Uses communications link to establish the most efficient loading of up to six
compressors on the same suction line.
Multi-compressor loading can be selected to give priority in different ways:-
a) runH uses Hours run on each compressor to determine which is best
compressor to start or stop. The compressor with the least run hours is best
to start, the compressor with the most runhours is best to stop.
b) LEAD Always start this compressor first and stop it last
c) LAG start this after LEAD compressor at maximum, OFF or tripped.
d) StBy Only start this compressor if another compressor is tripped.
Содержание SCC 25
Страница 12: ...Page 12 GUARDIAN SCC 40 Issue Auto VI V3 6t 07 12 00 Consultant Format SCC40 Std ...
Страница 51: ...Page 51 GUARDIAN SCC 40 Issue Auto VI V3 6t 07 12 00 Auto VI Drawing ...
Страница 52: ...Page 52 GUARDIAN SCC 40 Issue Auto VI V3 6t 07 12 00 Auto VI Wallbox Wiring ...
Страница 73: ...Page 73 GUARDIAN SCC 40 Issue Auto VI V3 6t 07 12 00 SCC 40 Enclosure wiring for trips negative ...
Страница 74: ...Page 74 GUARDIAN SCC 40 Issue Auto VI V3 6t 07 12 00 SCC 40 Enclosure wiring for trips positive ...
Страница 76: ...Page 76 GUARDIAN SCC 40 Issue Auto VI V3 6t 07 12 00 Standard Wallbox Internal wiring ...
Страница 77: ...Page 77 GUARDIAN SCC 40 Issue Auto VI V3 6t 07 12 00 Standard SCC 40 Drawing ...