RVS-DN, Digital Soft Starter Instruction Manual–4/01/04
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Physical Installation
Location of the RVS-DN is important to achieve proper performance and normal operating life. The
unit should be installed in an area where it will be protected from.
• Direct sunlight, rain or moisture
• Corrosive gases or liquids
• Vibration, airborne dust or metallic particles
When preparing to mount the RVS-DN, lift it by its base, never by the front cover. For effective
cooling as well as proper maintenance, the RVS-DN must be installed on a flat, non-flammable
vertical surface (wall or panel) using four mounting screws. There must be a minimum of 4.7 in.
clearance above and below the RVS-DN for sufficient air flow. A minimum of 1.2 in. clearance is
required on each side of the RVS-DN.
The protected chassis is rated to operate over a temperature range of -14°F (-10°C) to +122°F
(50°C).
Enclosures
If the RVS-DN is to be mounted in an enclosure, the size of the enclosure should be determined by
the heat dissipation. The RVS-DN’s watts loss is approximately 3 x the FLA in watts. (Example-for
a motor of 100A, expect the watts loss of the starter to be 300 watts.)
NEMA 1 enclosure–The NEMA 1 must be properly ventilated or additional fans may be needed.
NEMA 12 enclosure–The NEMA 12 enclosure will require some means of reducing internal
enclosure heating. This can be accomplished by:
• additional ventilation (fan and filters)
• bypass after acceleration option
Bypass After Acceleration Option
The bypass after acceleration option allows the RVS-DN to control the motor during starting and
stopping for smooth, stepless acceleration and deceleration. However, once up to full voltage the
RVS-DN is bypassed to eliminate the watts loss. After the soft stop is initiated the motor switches
back from bypass to the RVS-DN.
To maintain full motor protection while in bypass:
The preparation for bypass option requires bus bar extensions for frame sizes C through E. These bus
bar extensions can be ordered from Magnetek and field installed. The current transformers (CTs) are
moved up onto the bus bar extensions, allowing the bypass to be wired after the CTs. In this manner
the CTs are always monitoring current even in bypass mode.
Frame size A must be special ordered with preparation for bypass. Frame size A (8-72 amps) will
have 3 additional terminals labeled L1b, L2b, L3b. These terminals are wired in after the CTs,
allowing current to be monitored even while in bypass. Frame size B (85-170 amps) comes standard