Regulators - Section; Introduction; Receiving; Unloading - Cooper VR-32 Installation, Operation And Maintenance Instructions

VR-32 VOLTAGE REGULATORS - Section 1

INTRODUCTION

Cooper Power System's VR-32 feeder voltage regulators
are regulating auto-transformers. They regulate line voltage
from ten-percent raise (boost) to ten-percent lower (buck) in
32, approximately 5/8 % steps.
Cooper Power System's regulators are supplied with the
following standard features:
o
Dual-rated 55/65 C rise.
ADD-AMP capabiilty.
Unit construction.
Sealed-tank construction.
Pressure relief device.
High-creep bushings with clamp-type terminals.
MOV-type external series arresters.
Shunt arrester mounting bosses.
Two nameplates.
Gil sight gauge.
Upper filter press connection.
Drain valve and oil-sampling device.
o
The 65 C rise insulation system and the sealed-tank con-
struction allow for a BONUS CAPACITY 12% above the
o
55 C normal rating without loss of normal insulation life. The
BONUS CAPACITY is stated on the nameplate (such as
167/187 kVA for a nominal 167 kVA regulator), and is avail-
able when the ADD-AMP feature is not in use. All Cooper
Power System's regulators are manufactured and tested to
ANSI standard C57.15.
The unit construction, which suspends the internal
assembly and the control enclosure form the cover, allows
for ease of inspection and maintenance.
There are three types of step-voltage regulators: source-
side series winding, load-side series winding, and series
transformer. Cooper Power System's Regulators are usually
equipped with an equalizer winding. The nameplates locat-
ed on the tank and control box clarify the power circuit
involved.

RECEIVING

Inspection
Prior to shipment, the regulator is thoroughly tested and
inspected at the factory. Immediately upon receipt of the
regulator shipment, before unloading, a thorough inspection
should be made for damage, evidence of rough handling, or
shortages. The position indicator, junction box, arrester,
radiators, and bushings should all be inspected for evidence
of damage. Should this initial inspection reveal evidence
of rough handling, damage, or shortages, it should be
noted on the Bill of Lading and a claim should immedi-
ately be made with the carrier. Also, notify Cooper Power
Systems, 2300 Badger Drive, Waukesha, Wisconsin 53188,
attention Service Manager.

Unloading

When an overhead crane is used for unloading, the regula-
tor must be lifted by means of a sling and spreader bar uti-
lizing the tank-mounted lifting lugs which are shown in
Figure 1-2. Do not lift the entire unit with the lifting eyes on
the cover. The lifting eyes are only to be used to untank the
internal assembly which is attached to the cover.
WARNING: The cover may fracture if the cover-
mounted lifting eyes are used to fit the entire unit. Lift
the entire unit only with the tank-mounted lifing lugs.

Storing

If the regulator is not to be placed into immediate use, it can be
stored with minimal precautions. Locate the unit where the possibil-
ity of mechanical damage is minimized.
INSTALLATlON
Pre-installation Inspection
Before connecting the regulator to the line, make the following
inspection:
1 . Check the oil sight gauge. Look for visible signs of oiI leakage.
2. Examine the series arrester for damage. If damaged, install a
new arrester of the same voltage rating.
3. Inspect the porcelain bushings for damage or leaking seals. If
there is a suspicion that moisture has entered the unit, remove
the handhole cover and inspect for evidence of moisture such as
rust or watertracks in the oil. If moisture has entered the tank, dry
the regulator and filter the oil before putting the unit in service.
The oil must test 26 kV minimum in a standard gap (ASTM D
877). Be sure to properly replace the handhole cover.
CAUTION: Do not subject tap changer to tempera-
o
tures above 150 F. To do so may cause damage to
the contact panels, resulting in misalignment of the con-
tacts.
4. If the regulator has been stored for some time, test the dielectric
strength of the oil according to ASTM D-877.
5. The regulator may be energized at rated line voltage (with caution)
and an operational check, page 1-8, can be performed. (This
procedure is optional.)
6. A Hi-pot test may be done to insure adequate electrical clearanc-
es to ground. (This procedure is optional.)
S225-10-5
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