Carel MuChiller UCHBD00001130, User Manual

Page: 48 / 108

ENG
Compensation in cooling:
Fig.5.a
Key
Ext. Temp. Outside temperature
Std set Control set point
T1 Outside temperature to start compensation in cooling mode
T2 Outside temperature to end compensation in cooling mode
DT Maximum compensation value in cooling mode
Compensation in heating:
Fig.5.b
Key
Ext. Temp. Outside temperature
Std set Control set point
T1 Outside temperature to start compensation in heating mode
T2 Outside temperature to end compensation in heating mode
DT Maximum compensation value in heating mode
5.1.3 Request from BMS
The request can be managed directly from a BMS, bypassing normal temperature control and enabling
the external request signal (0-100.0%) via the specific Modbus serial variable (BMS_PwrReq, HR 331). This
operation is enabled via another serial variable (En_BMS_PwrReq, CS 22).
Note: if the supervisor is offline, the unit continues to operated in stand-alone mode, regardless of the
request from the BMS.
5.1.4 High evaporator outlet temperature alarm
μChiller activates an alarm when the evaporator outlet temperature exceeds the threshold set by the user
(via the offset relative to the control set point). When the outlet temperature exceeds the threshold, a
counter starts and after a delay (settable), the alarm is activated. An initial delay disables the alarm in the
transient period when the unit is starting.
Note:
l
the alarm is only available on chiller units.
l
the high temperature alarm can be used to activate a backup unit in critical applications.
User Code Description Def Min Max UOM
U SetA Current set point - -999.9 999.9 °C
S U031 High water temperature alarm: offset 10.0 0.0 99.9 K
S U032 High water temperature alarm: delay at start-up 15 0 99 min
S U033 High water temperature alarm: delay in operation 180 0 999 s
48 | 5. Functions
µC0300053EN rel. 1.0 – 23.07.2018