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47
Running in Full Load Mode
When the
F
ULL
L
OAD
command is received the Viltech disables all capacity control and locks the
compressor at the fully loaded position. However, normal limiting and unloading functions will still be active.
Anti-Cycle in Sequenced Mode
While in the
S
EQUENCED
mode the anti-cycle time takes on a new role. If the master sequencer requests a
RECIP compressor to stop but time is still remaining on the anti-cycle timer, the compressor will not stop. The
compressor will remain running, until the anti-cycle timer expires. This procedure ensures that the compressor
is always available for the next sequenced start. If the compressor should be stopped manually, or due to a
failure, with time remaining on the anti-cycle timer it would then be unavailable for sequencing until the timer
expires.
Forced Unloading & Limiting
F
ORCED
U
NLOADING AND
L
IMITING
are performed to protect the system under extreme conditions or to slow-
down the rate of capacity increase. The Viltech may unload the compressor or limit loading of the compressor due
to high discharge and suction pressure. In the Manual mode of operation and forced unloading is enabled.
Forced Unloading and Limiting will cancel any ongoing capacity control changes. If a parameter exceeds the high
limit setpoint the compressor will be limited (not allowed to load). If a parameter exceeds the high unload setpoint
the compressor will be forced to unload until the parameter is reduced.
Ramp Start
R
AMP
S
TART
adjusts the forced unloading and limiting setpoints during a period of time after the compressor is
started. Ramp start is used to reduce the demand power requirements during compressor startup. Each high
unload and high limit setpoint has associated with it a similar ramp unload and ramp limit setpoint. Also associated
with each different parameter is a ramp duration time. After the compressor has started, the forced unloading and
limiting setpoints are gradually changed from the ramp setpoints to the high setpoints during the ramp duration
time. The Discharge Pressure Ramp Start parameters are set-up on the Discharge Pressure Setpoints screen under
the
SETPT
hot key.
The relationship of the ramp start feature to unloading and limiting can be seen in the following figure.
Summary of Contents for Vilter VilTech
Page 1: ...VILTech micro controller Operation and service manual ...
Page 2: ...2 ...
Page 10: ...10 Notes Page ...
Page 11: ...11 ...
Page 16: ...16 ...
Page 18: ...18 ...
Page 29: ...29 ...
Page 38: ...38 ...
Page 53: ...53 ...
Page 88: ...88 ...
Page 138: ...138 ...
Page 142: ...142 ...
Page 145: ...145 ...
Page 147: ...147 ...
Page 153: ...153 ...
Page 154: ...154 Alarm and Failure Data ...
Page 155: ...155 Alarm and Failure Data Continued ...
Page 156: ...156 Alarm and Failure Data Continued ...
Page 158: ...158 Compressor State Table ...
Page 159: ...159 Last RECIPStart Status Table ...
Page 172: ...172 ...
Page 173: ......