9146600990 Rev M
BE1-25A Testing
5-1
SECTION 5 • TESTING
GENERAL
BE1-25A Auto-Synchronizers are calibrated and tested for correct operation at the factory and all calibration
pots are sealed. Im mediate ly upon re ceipt of the rela y, o r after exten ded service, it is recommended that the
VERIFICATION TESTS
in this section be performed. These comprehensive tests verify all operating
parameters.
OPERATING PRECAUTIONS
Before operation, note the following precautions.
•
Always be sure that external operating (monitored) conditions are stable before removing a BE1-25A
unit from serv ice.
•
The BE 1-25 A is a solid-s tate device an d ha s be en type tested in acc orda nce with the req uirem ents
defined below under Dielectric Test. If a wiring insulation test is required on the switchgear or panel
assembly of which this unit is a part, see
Dielectric T est
below.
•
Be sure that the BE1-25A case is hard wired to earth ground using the ground terminal (A1) on the
rear of the u nit.
•
When the unit is in service , the contro ls should be protec ted by the plastic cov er su pplied. This limits
access to the control settings.
DIELECTRIC TEST
In accordance with IEC 255-5 and ANSI/IEEE C37.90-1978, one-minute dielectric (high potential) tests up to
150 0 Va c (45 -65 h ertz) ma y be perfo rmed. N ote that:
•
Decoupling capacitors are employed from all terminals to ground. Accordingly, a leakage current of
approximately 20 milliamperes is to be expected when high potting at 1500 Vac, 60 hertz.
•
Varistors are connected across all terminal-pairs of terminal strip TB1, and across terminals 21/22 of
TB2. Do NOT high pot from terminal to terminal across these varistors. Normal high pot procedures
(high potting from term inal to fram e) are no t affected by these v aristors.
•
A one megohm resistor is used in the contact sensing input circuit between the minus supply and the
chassis. High potential testing on these contact sensing inputs (TB1, terminals 3, 4, 5, 6, 9, 10, 11, 12,
13, 14, 15, and 16), (TB2, terminals 21 and 22) may damage the internal resistor. Use a high
resistance tester (megger) or alternate means to test these contacts.
APPLICATION
General Information
Although operation of BE1-25A Auto-Syn chronizers is straightforward, the following suggestions are offered.
•
When using the LOAD switch, there is a built-in delay before the display responds to the command.
This delay is for the purpose of security — so that a deliberate action is required to effect a change,
not an accidental bump. (If the switch is released before display acknowledgment, the original setting
is retained.)
•
Da she s in the display indicate an op en inp ut or out-of-rang e co ndition.
•
When power is first applied to the unit, the display defaults to Function P, at which position the display
functions as a digital synchroscope. This default also occurs whenever the unit is RESET.
•
In an ideal syste m, a smoothe r closing res ults wh en the generator speed and voltag e are exactly in
synchronism with the system. Depending on the system, this usually is not possible. Closing from the
high side w ith GF > BF usu ally res ults in less stre ss o n sy stem com pon ents . Contac t sensing inputs
can be set so that the synchronizer only allows closing when GF > BF and/or GV > BV.
•
Setting MAX SLIP too low can result in excessive hunting by the governor. A low inertia system driven
by an internal combustion prime mover is especially prone to this, since the power strokes can (prior
to breaker closure) modulate the fundamental frequency of the generator output. If the resulting
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