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The MPR has a normally closed N/C alarm contact (rated 5 A 250 V resistive load). It will be possible to give an
external alarm signal. This contact is signed with X1 and X2 (ALARM) in the base of the regulator.
When alarm condition disappears, the regulator will reset itself automatically.
••••
No Supply voltage alarm
When the voltage supply is lost, the digital display is off and the alarm contact (X1 and X2) is closed.
••••
Low PF value in the network
If after 15 minutes the preset PF is not achieved, the alarm contact closes and the actual PF is displayed.
At the same time the CosØ Led flashes. The contact closes again when the preset conditions are met.
The CosØ led however continues to flash until the RESET PROCEDURE is performed.
••••
Voltage alarm
When the supply voltage is higher than 110% of the rated value (for at least 10 secs.), the regulator will
switch off, step by step, all capacitors banks. Under such condition the MPR displays the VOLTAGE value,
the related VOLT led (V) flash and the N/C alarm contact for the external signal ( X1 - X2 ) will close.
The alarm condition will clear when the voltage is again within correct parameters. The "V" Led however
will continue to flash in order to show, to the operator, which alarm condition was on. To reset the alarm
memory the RESET PROCEDURE should be performed.
WHEN THE VOLTAGE ALARM CONDITION IS ON, ALL MANUAL AND AUTOMATIC OPERATING
FUNCTIONS ARE UNAVAILABLE.
••••
Current signal alarms
⇒
⇒
⇒
⇒
Max current. It occurs when the current value in the secondary of the CT transformer is higher than
5Amps (for at least 10 secs). In such a condition, the MPR displays the CURRENT value, the related
CURRENT Led (A) will flash and the N/C alarm contact ( X1 - X2 ) will close. The alarm fault condition
clears when the current returns to rated conditions. The "A" led however will continue to flash in order to
show, to the operator, which alarm condition was on. To reset the alarm memory the RESET
PROCEDURE should be performed.
⇒
⇒
⇒
⇒
Min current alarm. It occurs when the current value in the secondary side of the CT transformer is
lower than 500 mAmps (for at least 10 secs). In such a condition, the MPR displays the CURRENT value
will flash. When the Min current alarm is operating, the MPR is only able to switch off the capacitor banks
if the PF value is more than 1. The alarm fault condition clears when the current returns to rated
conditions.
⇒
⇒
⇒
⇒
Current lower than 10 mAmps. In this condition the regulator will only operate in MANUAL mode. The
numerical display will show the symbols"-.--", and the related CURRENT Led (A) will flash. The N/C alarm
contact ( X1 - X2 ) will close. The alarm fault condition clears when the current returns to rated conditions.
The "A" Led however will continue to flash in order to show, to the operator, which alarm condition was on.
To reset the alarm memory the RESET PROCEDURE should be performed.
••••
Temperature alarm (only for MPR8)
The MPR8 regulator incorporates a temperature control circuit. The temperature sensor must be
connected with the regulator switched off.
⇒
⇒
⇒
⇒
First step (35°C). Causes the N/O contact (5 A 250 V resistive load) connected to terminal P1 and P2
(VENT) to close. The temperature differential is 5 °C. This contact should be used to control the pane l
ventilation fans.
⇒
⇒
⇒
⇒
Second step (50°C ) The regulator will rapidly switch off all capacitors banks. With this alarm condition,
the MPR displays the TEMPERATURE value, the related TEMPERATURE Led (°C) will flash and the N/C
alarm contact for the external signal ( X1 - X2 ) will close. The alarm fault condition clears when the
temperature value falls below 45 °C. The "C" Led ho wever will continue to flash in order to show which
alarm condition was on. To reset the alarm memory state the RESET PROCEDURE should be performed.
WITH THE MAXIMUM TEMPERATURE ALARM CONDITION ON, ALL MANUAL AND AUTOMATIC
OPERATING FUNCTION ARE HALTED
••••
Supply interrupts
To avoid dangerous operating condition on contactors when the supply voltage is interrupted, the MPR
switches off all capacitors banks until reconnection. Micro breaks trouble on network must be solved by
the client.
RESET PROCEDURE
It is necessary to select the values corresponding to the flashing Led (alarm memory state condition) and
press the
Prog.
button.
8. WORKING TROUBLES and SOLUTION
Most malfunctions are caused by incorrect connections. The most common faults are as follow:
