Baldor MN770 - Manual (Page 25)

Section 1
General Information
5-4 Set-Up Information MN770
Recommended Power Up/Down Sequence for Elevators Using DC SCR Controls
The following is a recommended sequence for turning on and off the elevator drive and
external OEM control. Figure 5-4 shows this sequence.
Figure 5-4 Typical Power Up/Down Sequence for DC SCR Controls.
M Contactor
Armature Enable
20msec
20msec
Field
“Drive ON”
Opto Output
Brake Release Signal
(from elevator controller)
50msec
Speed Command
50msec
RUN TIME TURN-ON TURN-OFF
Brake Set Time
Open
Closed
Open
Closed
Off
On
Off
On
Economy
Forcing
Running
Off
On
Disengaged
Engaged
Zero FPM
Contract Speed
Disengaged or “Picked Up”
Engaged or “Set”
Standing or Economy
Forcing or “Leveling”
Running
Sequence:
1. Close the M Contactor. Approximately 20msec is required for the contacts to
close and connect the Control to the Motor and complete the armature loop.
2. The filed is controlled independently of the armature. The field can be at
running voltage (or at forcing voltage) prior to actual commanding speed.
3. Armature enable (pin J1-8 of the DC SCR Control) allows the SCR’s to begin
firing.
4. The “Drive ON” Opto output from the DC SCR Control provides an indication
(for the elevator control) that the drive is ready to act on Speed or Torque
commands.
5. Zero speed command should be held until the brake has actually disengaged,
allowing the car to move.