User Manual

Copyright © 2011 Howard Industries, Inc.
Howard Industries, Inc.
Laurel, MS 39440
www.howardtransformers.com
Document No. 2.4.136
Revision: 0
Issued: December 2, 2011
2
• Oil ll/oil level plug
• Oil drain valve with sampling device
• Automatic pressure relief device
• Dial-type liquid level gauge
• Dial-type liquid temperature gauge
• Electrical grade mineral oil insulat-
ing uid with oxidation inhibitor
• Laser engraved nameplate
• Bushing designation labels
Optional Features
• Insulated interphase barriers
• Two 2.5% high-voltage taps above
and below normal voltage, or four
2.5% high-voltage taps below
normal voltage, or four 2.5% taps
above normal voltage, or no high-
voltage taps
• Dual high-voltage rating with non-
loadbreak switch handle located in
the high-voltage compartment (not
available in combination with high-
voltage taps)
• High-voltage fuses, including
internal expulsion fuses, draw-out
expulsion fuses, internal backup
current limiting fuses, and draw-out
full-range current limiting fuses in
dry-well canisters
• Internal load-break high-voltage
ON/OFF switch with operating
handle located in the high-voltage
compartment
• Stainless steel tank and terminat-
ing compartment
• Flip-top hood on terminal
compartment
• Cover mounted high-capacity pres-
sure relief device
• Rtemp
®
, silicone, or seed-based
vegetable oil insulating uid
• Cooling fans with control or fan
mounting provisions only
• Mounting provisions for external
electricity meter
• Hexhead security bolt (pentahead
standard)
• Temporary service access provision
(conduit hole) in terminal compart-
ment sill
• Optional topcoat paint color: ANSI
49 light gray, ANSI 61 light gray,
ANSI 24 dark gray, olive green
(Munsell 7GY3.25/1.5), or white
• Tank grounding connectors
Unit Substation Designs
In addition to the standard pad-
mounted compartmental design
previously described, Mobile
Power transformers can also be
supplied in a unit substation design
(Figure 2), available with a variety
of different high-voltage and low-
voltage termination interfaces, such
as full-height anges, throats, or air
terminal compartments. Substation
transformers are available in
capacities through 10,000 kVA, with
high-voltage ratings up to 69 kV.
Mobile Power Transformers
Catalog Section 91-20
Document 2.4.136, Revision 0, December 2, 2011
Copyright © 2011 Howard Industries, Inc.
Laurel, Mississippi
Telephone: [phone]
Fax: [phone]
E-mail: [e-mail]
Web: howardtransformers.com
Figure 2: Typical unit substation transformer.
91-20
Mobile Power