KGL Operating Manual – VS 3010 BS
2018-07-02
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51 178
The variable time is inversely proportional to the control error. In the case of maximum control error, the
variable time tv approaches zero. In the case of declining control error, the time tv is automatically increased
up to the specified maximum time. The basic time and the maximum variable time for the shifting up (switching
on) and shifting down (switching off) are parameters that can be configured for every loading / unloading of a
condenser stage. The following apply for determination of the control times:
t = tb + tv
The following applies:
for dt > dt_max and dt = dt_max
tb = basic load time (configurable for each stage)
tv = variable control time
tv_max = max. control time (configurable for each stage)
dt = control error
dt_max = max. control error (configurable)
The run time is calculated for each controller cycle. In each case, the variable time is recalculated and the
elapsed time since the last switching point is compared with the calculated time. If the calculated run time is
less than or equal to the elapsed time, fan activation is performed if the control error is greater than the
specified neutral zone. The following diagram shows the calculation of the control time:
4.5.11 Protection and base load rotation of the fan motors
Additional functions for the protection of the fan motors are implemented for the pack controller. In months with
low outdoor temperatures when only a small part of the condenser fans is needed, it can happen that fans
seize up after long standstill time. A long lasting standstill time can be prevented using the parameter
(menu 3-6) to prevent this seizure. If base load rotation is activated, the following additional
BaseLoadRot.F
entries are displayed on the operating screen:
1. Parameter "On time cond."
You can select between 2 operating modes:
Fan protection