1. SmartBank
Metal-Enclosed
™
Power Capacitor Banks
Medium Voltage • Fully Configurable
Look to Maysteel for the finest in medium-voltage, metal-enclosed banks having
capacitive reactive power ratings up to 30 MVAR in a single enclosure. These
robust units are designed to improve power factor in a variety of industrial, com-
mercial and utility applications.
Both fixed designs and automatically switched designs (up to 20 steps) are
available, in system voltages from 2.4 kV through 34.5 kV RMS. Metal-enclosed
versions are designed for substation use; pad-mount versions are for use in
publicly accessible areas. Other major features include:
• Free-standing, heavy-gauge, compartmentalized Maysteel enclosures
• Both front and rear doors for easy accessibility
• Integral control and protection systems
• Short circuit ratings to 61 kA RMS symmetrical
• Fused main disconnect switch or interlock with grounding switch
• Available fully assembled, or shipped in sections for field assembly
• All equipment meets or exceeds ANSI, IEEE, NEC and NESC standards
ISO 9001
CERTIFIED
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2. Viewing windows
available as option. Enclosure
Easy access
Features
control cabinet.
Doors equipped with three-point latching
mechanism, padlockable handles.
Mesh-backed
ventilation louvers
allow filters to be
changed without
opening enclosure.
Key interlock system ensures
safety through proper sequence
Robust, formed-channel base simplifies of operation.
installation, allowing single-piece shipments
in lengths up to 50 feet; constructed of
7 gauge hot-rolled steel or 304L stainless
steel (optional).
• Standard construction: 12 gauge hot rolled steel construction,
pickled and oiled ASTM A569, Type 1010.
• Optional constructions:
11 gauge hot rolled steel Galvanneal A60 grade
Aluminum 304L or 316 stainless steel
• Polyester powder coat finish. Available colors:
Gray – ANSI 61, Munsell 8.3BG 6.10/0.54
Gray – ANSI 70, Munsell 5BG 7.0/0.4
Green – Munsell 7GY 3.29/1.5
• Degrees of protection: NEMA 3R standard; NEMA 1, 4X, 12 and 13 optional.
• Fan system in NEMA 1 and 3R enclosures; air conditioning in
NEMA 4X, 12 and 13.
• Stainless steel hinges, hinge pins, fasteners and associated hardware.
• Doors on front and rear of enclosure for easy access.
Seam cap, drip edge and
pitched roof provide maximum • Control compartment equipped with thermostatically controlled heater
rain protection. and GFI duplex outlet.
• Interior lighting in control compartment, main disconnect compartment
and all compartments containing medium-voltage power components.
3. Electrical
Features
Controllers can switch stages based
on current, power factor, temperature, Main fuses provide
time or voltage. over-current protection
to main bus, back-up
protection to power
components.
AUtO / OFF / ON Arresters protect from transient
switches, and Stage over-current caused by lightning or
OFF and Stage ON switching. Heavy-duty distribution
press-to-test pilot lights. class arresters standard; intermediate
station class optional.
Fused control power
transformer is located
ahead of main disconnect,
allowing control and
protection circuits to
be tested before main
power is applied.
Main disconnect switch, located in
isolated compartment, allows arresters,
main fuses and other components to be
serviced without the need to disconnect
power to the feed bus.
Metal-Enclosed,
Power Capacitor Banks
4. Air-insulated, load-break main disconnect switch equipped with mechanically
interlocked ground switch, which grounds the load-side for safety during maintenance.
External operation provides the visible break required by National Electrical Code.
Copper power bus rated at 1,000
amperes RMS per inch2 throughout.
Ground switch
transient Inrush Reactors
Multi-stage power capacitor banks are equipped with air-core, dry-type, single-
phase transient inrush reactors that reduce the frequency and magnitude of the
inrush current that result from back-to-back switching of stages.
5. Capacitor banks are configured ungrounded
wye standard, delta or grounded wye optional.
Externally fused units are standard, internally
fused available upon request.
All capacitors use environmentally friendly,
biodegradable dielectric fluid with no
PCB content.
Internal discharge resistors reduce residual
voltage to less than 50 volts within five minutes
of de-energizing.
low-loss, double-bushing capacitor units
meet or exceed IEC 871 and IEEE Standard 18.
Rear-entry doors provide easy access to
capacitor units; simple capacitor mounting
system facilitates removal and change-out.
Each capacitor unit is protected against case rupture
by a current-limited fuse with a 63kA RMS symmetrical
interrupting capacity.
Stages are controlled by single-phase vacuum
switches (pictured), single-phase oil switches,
three-phase vacuum interrupters or three-phase
vacuum contactors.
Automatic detection system provides both local and
remote indication that one or more capacitor unit fuses
in a stage has operated.
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