DATAKOM DKG-705 User’s Manual
705_USER.doc
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10.4 OVER/UNDER VOLTAGE FUNCTION
The mains phase voltages are measured twice a second and compared with predefined high and
low limits. If at least one of the phase voltages is outside limits, this will mean a mains failure. The
response time is approximately 500ms.
Related parameters:
P_512 Mains Voltage Low Limit
P_513 Mains Voltage High Limit
10.5 MAINS REVERSE POWER FUNCTION
The mains active power is measured for each period. If the genset supplies power to mains and
this power exceeds the predefined limit this will mean a mains failure.
The mains reverse power detector has a variable response time. For a power not exceeding 2
times the predefined limit the response time is 8 cycles. The response time is reduced with larger reverse
powers. It is approximately 1 cycle with a reverse power of 8 times the predefined limit.
If mains current transformers are not fitted, the mains reverse power protection will not operate.
Thus a full version of DKG-705 is required for this protection.
Related parameters:
P_633 Mains Current Transformers
P_A24 Reverse Power Limit
10.6 NO FREQUENCY FUNCTION
The unit counts the time after the last detection of the mains frequency pulses. If no mains
pulses is detected for a period corresponding to 2,5 times the Mains Frequency Low Limit (
P_522
), a
mains failure alarm is generated.
Related parameter:
P_522 Mains Frequency Low Limit
