Inspection And Tests; Inspection And Testing; Inspection; Testing - Siemens WL Series Instruction & Installation Manual

Type WL Low Voltage Metal-Enclosed Switchgear

Inspection and Tests

Hazardous voltage.
Will cause death or
serious injury.
Keep out.
Qualified personnel only.
Disconnect and lock off all power before
working on this equipment.

Inspection and Testing

Before the equipment is energized, it must be thoroughly
inspected and tested. Correct any deviations before energization.

Inspection

Check the following points:
1. Power connections and secondary control connections prop-
erly made and checked for shorts and undesired grounds.
2. Electrical disconnecting contacts, machined parts, shutters,
etc., checked for lubrication and operation.
3. Blocking supports and other temporary ties removed from
breakers, instruments, relays, etc.
4. Proper fuses correctly placed.
5. After external connections have been made, check that
temporary wiring jumpers (used on the secondaries of
current transformers tied to external devices, as shown
on wiring diagrams) have been removed.
6. Ground connections properly made.
7. All equipment which has been removed during assembly
has been replaced.
8. Trip devices and/or relays coordinated with other pro-
tective devices on the system. Refer to protective device
instructions before making any adjustments. Consult the
local utility before making any connections to the power
supply system.
9. Storage battery fully charged and battery charger operating
correctly (For DC control source only).
10. Interlocks performing properly.
11. Circuit breakers checked and prepared per instruction
manuals.
12. All filters in vent area are clean and free of shipping or
construction material.
13. All tools removed from equipment, and equipment clean.

Testing

1. A megger test is made on the high voltage circuit to be
sure that all connections made in the field are free of
undesired grounds. A megger test is also advisable on
the control circuit.
2. A dielectric test, if possible, should be made on the high
voltage (power) circuit for one minute at the appropriate
test voltage. (Voltage transformers, control power trans-
formers, surge arresters, and surge capacitors must be
disconnected during this test).
Rated voltage of circuit
480 or 600 volts
208 or 240 volts
Secondary & control circuits
22
Courtesy of NationalSwitchgear.com
DANGER
Figure 31. Circuit Breaker
Position Indicator and
Connected positions)
Test voltage
75% of 2200 = 1650 VAC
75% of 1500 = 1125 VAC
75% of 1500 = 1125 VAC
Note: Certain control devices, such as motors and motor
circuits, should be tested at 675V AC. Electronic devices
should be tested at the voltages specified in the instruction
manual for the electronic device.
In accordance with ANSI C37.20.1, Field Dielectric Tests are also
recommended when new units are added to an existing installa-
tion, or after major field modifications. The equipment should
be put in good condition prior to the field test. It is not expected
that equipment shall be subjected to these tests after it has
been stored for long periods of time or has accumulated a large
amount of dust, moisture, or other contaminants without being
first restored to good condition.
Excessive test voltages may result in damage to
equipment.
Do not perform dielectric tests at test voltages exceed-
ing the ratings of the tested equipment.
3. With circuit breaker in the TEST position make the following
tests on each unit:
A. Trip and close the circuit breaker manually, and electri-
cally if breaker is electrically operated.
B. Use a trip test set or other suitable source of current
to trip the circuit breaker through the trip device.
C. If protective relays are provided, trip electrically operated
circuit breaker by passing sufficient current for voltage,
(if applicable) through the coils of protective relays.
D. Trip and close electrically operated circuit breakers from
any remote control locations.
E. Operate auxiliary device (e.g., MOC or TOC switches) to
confirm correct operation.
F. Test the phase sequence of polyphase high voltage
circuits, particularly those used for motor starting.
G. Perform other tests and checks in accordance with the
circuit breaker and trip device instruction manuals.
H. Test for correct phasing across the bus tie circuit.
4. Current transformer circuits are tested for continuity. As
shown in Figure 23, with the switchgear installed but not
energized, disconnect the "grounded" lead at the current
transformer secondary terminal block connection, and
pass a measurable amount of current not to exceed five
amperes through the lead to ground. Pass sufficient
current to observe operation of relays and instruments.
Manipulate the instrument switches and observe the
phasing. Repeat with each transformer. Do this for
metering and relaying current transformers only - not
breaker tripping transformer.
CAUTION