Installation and Operating Instructions - Crompton Instruments

TYPE 25 — SYNCHRONISING/SYNCHRONISM-CHECK
This function operates as a permissive relay, where the ‘not tripped’ condition indicates that the
two systems are within the permitted limits to allow synchronism. A ‘tripped’ condition indicates
that the systems are not within the allowable limits, and synchronism is not possible.
The status display will indicate 25# (relay is tripped) when the relay is not in synchronism. The
display indication will disappear when synchronism is achieved.
When failsafe is set to ‘yes’, the relay contacts will energize when the GEN and BUS circuits are
in synchronism. An out-of-sync condition, or loss of auxiliary supply, will de-energize the relay
contacts.
Brief details
The permissive relay operates when the “Bus” and “Generator” signals are within the selected
limits of frequency, phase angle, voltage and the phase sequence of the “Generator” voltage
inputs are correct for the duration of the selected delay to permit or to cause the paralleling of
two circuits. The relay will return to the “tripped” condition when any one of the conditions
detailed above become invalid. The time delay is used on the transition to the “not tripped”
condition.
Parameters
You must specify the following parameters for operation of the synchronising relay:
●
The maximum permitted phase angle between the “Bus” input voltage and the
reference “Generator” voltage (V1, VA, or V1-2),
●
The maximum permitted voltage difference between the “Bus” input voltage and the
reference “generator” voltage,
●
The maximum permitted frequency difference between the “Bus” and “Generator”
(slip frequency)
●
The qualifying time for which these conditions must be true
• The minimum voltage level below when function is disabled.
Parameter details
Range of Phase Difference (PhAngle) 2 — 20 degrees
Range of Voltage Difference (VDelta) 0 — 20% of nominal input voltage
Range of minimum Voltage level (Vmin)5- 119% of nominal input voltage
Range of Time Delay (TimeDelay) 0 to 5 seconds
Range of slip frequency (SlipFreq) 0.1 — 1 Hz
Voltage Accuracy
± 2% of nominal input voltage
Resolution of slip frequency
0.1 Hz
Frequency Accuracy
± 0.1 Hz
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