ECKELMANN VS 300, Руководство по эксплуатации

Страница: 46 / 172

Function of VS 300
38 Doku-Version 2.05 - Firmware 2.10 - 15. September 2017
4.3.16 Response to fault conditions
Can bus fault on individual stations:
If no telegram is received from a given case/coldroom controller during a time longer than the timeout period for
load level reception, the mean load level for the controller concerned will be ignored until such time as a new
telegram is received.
Global bus fault:
The current t
0
setpoint is retained. At the end of a 10-minute alarm delay, a No Load Level fault is logged and is
not reset until new load level information is received via the CAN bus.
4.3.17 Demand-dependent setpoint shift parameters
The range within which t
0
can be changed is defined by the parameters t
0
-max and t
0
-min (Menu 3-2-3).
Change to the second setpoint does not take place with demand-dependent setpoint shift.
The Max.LoadLevel parameter (Menu 3-2-2 (RK1) / Menu 3-3-2 (RK2) / Parameter S501/S51) defines the maxi­
mum load level (valve opening) for decrease of the t
0
setpoint.
The Min.LoadLevel parameter (Menu 3-2-2 (RK1) / Menu 3-3-2 (RK2) / Parameter S502/S52) defines the mini­
mum load level (valve opening) for increase of the t
0
setpoint.
The Increment parameter (Menu 3-2-2 (RK1) / Menu 3-3-2 (RK2) / Parameter S503/S53) defines the increment
in Kelvin by which the t
0
setpoint is increased or decreased after a definable time interval expires.
The Interval parameter (Menu 3-2-2 (RK1) / Menu 3-3-2 (RK2) / Parameter S504/S54) defines the interval in
minutes that must expire before the t
0
setpoint is updated as required.
4.3.18 Compressor control by refrigeration point
Control of compressors by either suction pressure or direct by the refrigeration point must be programmed on
the pack controller. Parameter S315/345: 0 = Pressure control, 1 = Refrigeration point.
The CAN bus node address of the refrigeration point that controls the compressor pack must be defined by Pa­
rameter S316/346. The fault message
No UA300 or EA 224 will be displayed after a delay of 5 minutes if no
UA300 is available under the CAN address entered.
With control by refrigeration point, the method varies according to whether the compressors are controlled by
step controller or speed controller.
Compressor control by step controller:
When control loop CLx contains only one compressor, the compressor output follows the refrigeration point's
solenoid valve. When more than one compressor is installed, the first compressor is loaded without delay.
Additional loading of compressors takes place after a programmable basic time tb elapses. The compressor
loaded each time is that having the shortest run time. If capacity stages are to be unloaded, a single compressor
is shut down without delay. When more than one compressor is installed, the first compressor is unloaded with­
out delay.
Additional unloading of compressors takes place after a programmable basic time tb elapses. The compressor
unloaded each time is that having the longest run time. Suction pressure in control loop CLx is additionally moni­
tored by the pressure transducer. When pressure drops below a definable low limit, the compressors are dis­
abled until such time as pressure again rises above the low limit.
This low limit monitoring corresponds to limit monitoring in normal operation as a suction pressure controller
(see Section 3.4.2 Low Pressure Monitoring). Monitoring of compressor starts is not active when compressor
control by refrigeration point is in effect.