CD Automation Revo M 2PH, Руководство пользователя

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CD Automation srl REVO M User’s Manual
CD-Eng-REVO-M-2PH-30-40A-Thyristors-Units
35
14 Heater Break alarm and SCR short circuit (HB Option)
Caution: to work properly the load must be powered at least about 160msec.
The Heater Break circuit read the load resistance with an Internal voltage transducer and Internal
current transformer (C.T.), to calculate the resistance (V/I).
Minimum current is 10% of the current transformer size.
If load current is below this value the Heater Break Alarm doesn’t work properly.
14.1 Heater break Calibration procedure
An automatic function sets the Heater Break Alarm ,when write in the parameter

the load current
and in the parameter  the load voltage.
If the load resistance increases due to a partial or total load failure ,the HB alarm become ON and alarm
relay change status.
You can Adjust the sensibility of HB alarm by using the parameter
 This parameter is set between
1 and 255% of the nominal resistance.
This parameter is the maximum increment of the resistance Load to establish the HB Alarm.
There is also
 parameter to set a delay to have HB alarm active.
14.2 HB alarm contact (digital output)
The Revo unit with HB option, is supplied with Heater Break alarm contact normally opened (NO):
 In normal conditions (without alarm) and with auxiliary power supply, the contact to the terminals
has opened (relay coil energized).
 In alarm condition or without auxiliary power supply the contact to the terminals is closed (relay coil
not energized).
This alarm can be configured in order to activate itself after that one of these alarms occours:
 HB and SC alarm are active.
 Only HB alarm is active.
 Only SC alarm is active.