KSQ332EJD22 - BUS COUPLER RELAY WITH DEAD BUS AND/OR DEAD INCOMER
- Precision Bus Coupler and Check Synchroniser
- Dead-bus facility
- Dead-incomer facility
- Bi-directional synchronising
- Integral voltage differential protection, adjustable
- "Easy view" status presentation
- Generator speed reference (analogue output)
- System status output
Description
KSQ332EJD22 provides both visual speed rotation, phase angel relationship and relay signal necessary to permit check synchronising of bus-tie breakers or dead-bus / dead-incomer connection. When used as a dead-bus or dead-incomer, the CB close relay will energise when either the bus I and/or bus II is "dead" AND the enable signal is closed.
The synchronising relay will close when the incomer (generator, busbar,
etc.) voltage and phase angle have been within the limits during the set
retention time.
A green lamp will indicate the close command to the breaker.
There is lamp indication for reference source present (BUS I) and incomer status (BUS II).
A green lamp (VOLT OK) is lit when both voltages are within the set limits.
KSQ332EJD22 is only available with separate AC or DC auxiliary supply.
Applications
KSQ332EJD22 is to be used as bus coupler. Any two phases (or phase-neutral) can be used for synchronising as long as it is the same two phases on both side of the breaker.
The unit is meant for manual and semi-automatic synchronising only since there is no compensation for the breaker closing time.
For automatic synchronising, the KCQ104x2 "SPOT ON" principle should be used to obtain compensation for breaker closing delay.
User setable limits and retention time on the rear.
The analogue -10/0/+10mA output signal can be used as speed reference to
a generator controller, with polarity and amplitude proportional to
frequency difference between the two systems.
System status:
KSQ332EJD22 is fitted with a system status relay. As standard the unit is powered from generator side (terminal 3 & 4), when power is ok and unit is working correctly the relay activates. It will release on alarm or when unit is not powered. Separate auxiliary supply is needed for continuously system status.
Normal operation : Closed contact
Alarm condition/unpowered : Open contact
System "S" the sector synchronising principle
The KCQ332JD22 is a low differential bi-directional check synchronising relay.
The synchronising relay closes when the incomer frequency is close
enough (diff 0,018 - 0,83Hz) to stay within the phase angle sector (S) for
the set retention period (t).
Sector synchronisation is the classical alternative for applications
which allows synchronisation accuracy and speed of synchronisation to be
interrelated. There is no compensation for the breaker closing time.
Approximate synchronisation accuracy relative to 12 o’clock position (Df) can be calculated by the following formula:
Df = (S : 360) / t (secs)
Example: Set phase angle (S) to 10 degrees and retention time (t) to 500mS to obtain an accuracy of Df:
(10/360) / 0,5 = 0,055Hz
If the phase angle limit is set too low and retention time too high for
very low differential synchronising, it can be difficult to achieve
synchronisation. If there is a continuously fluctuating load between the
two systems (for example to synchronise against a shaft generator when a
vessel is in rough weather), the KCQ104x2 "SPOT-ON" principle is more
suitable.
The "phase angle" setting on the rear of the unit refers to the total phase angle sector (S), centred about 0°. Hence a setting of 10° means the sector spanning from -5° to +5°.
