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.

TURN-ON

RUN TIME

TURN-OFF

M Contactor

Closed

 

 

 

 

Open

 

 

 

 

 

 

 

 

 

 

 

 

20msec

 

 

 

 

 

Armature Enable

On

 

Off

 

 

 

 

 

 

 

 

 

 

Forcing

Field

 

 

 

 

Running

 

 

 

 

 

 

Economy

ªDrive ONº

On

 

Opto Output

Off

 

 

 

 

 

 

 

 

 

Brake Set Time

Engaged

Brake Release Signal

(from elevator controller) Disengaged

50msec

Contract Speed

Speed Command

Zero FPM

Closed

Open

20msec

On

Off

Forcing or ªLevelingº

Running

Standing or Economy

Engaged or ªSetº

Disengaged or ªPicked Upº

50msec

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 ªDrive ONº 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.

5-4 Set-Up Information

MN770

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Baldor MN770 Contactor, Armature Enable, Field, ªDrive ONº Opto Output, Brake Release Signal, Speed Command, Sequence

MN770 specifications

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