TREND NX Variable Speed Drives - Manual (Page 16)

Installation on a Trend System
2.2.3 NX drive with Direct On line bypass
In this application the drive can be bypassed.
An Emergency Stop (ES) contact has been added in series with the start/stop
contact which will disconnect the C1 coil, and isolate the drive, and switch it
off via the C1 contacts.
The bypass is operated by a 3 position switch (NX, Off, Bypass).
In the NX position, the time delay contactor, T1, will cause C2 to operate. C2
is mechanically interlocked to C3 so that as C2 closes C3 cannot close and
stops the motor supply being connected back to the input. Closing C2 also
powers up C1 which puts power on the drive and starts it via terminals 6 and 8.
In the Off position, both drive and bypass are isolated so the motor is off.
In the Bypass position, C3 operates which bypasses the drive via C3 contact
and stops the supply being fed back to the Drive via the open C2 contact.
Another open C2 contact isolates the C1 coil and stops the drive starting. If the
overload contact operates, it opens the bypass, and also de-energises the C3
coil which drops out the C3 bypass contact.
14 NX Variable Speed Drives Installation Manual TG200434 Issue 3/A 04/07/2006