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VMX
2
Series Digital Solid State Soft Starter User Manual
83 |
P a g e
Appendix 4 (cont.) External OL Relay Applications
SPECIAL MOTOR APPLICATIONS
2S2W Motors
2-speed / 2-winding motor applications require a separate OLR sized for
each set of windings. These would need to be external OLRs.
In this example:
The
VMX2 Series
is used ahead of an
existing
2S2W starter, which
already has separate OLRs for each speed. Dry Aux. contacts of the
2S2W starter are used to provide a Run command to the
VMX2 Series
so that all existing controls can be used. In addition, another dry Aux. of
the Fast contactor is used to select Ramp 2. When started in Slow,
Ramp 1 (default) is used. If started in Fast, different ramp settings are
necessary so Ramp 2 is used. (See section 4.2.5a for Dual Ramp info.)
Either OLR will trip the VMX2 Series
, which will display [ Ptc] and light the “Overload” LED.