Trouble shooting, Load power is maximum and cannot be reduced, Load voltage snaps on – Precision Control Systems 1032 User Manual

Page 10: No load power, Maximum load voltage cannot be reached

Advertising
background image

Model 1032

8 of 9

Part No. 5000095-1011-6 6/13/2003

Two LED's on the circuit board may be used to aid

in determining problems with the controller.
The 'SSR DRIVE'

LED

varies in intensity proportional

to the drive signal to the Solid State Relay and is

proportional to the load voltage.
The 'LOAD CURRENT'

LED

varies in intensity

proportional to the current through the load. If the

load current reaches the current limit setting, the

intensity of the 'LOAD CURRENT'

LED

will no

longer increase and the load current will remain

fixed.

TROUBLE SHOOTING:

CAUTION: High voltage exists on the supply

and load terminals of this controller, and

may exist on other equipment located near

the controller. Use extreme caution to avoid

electrical shock.

LOAD POWER IS MAXIMUM AND

CANNOT BE REDUCED:

'SCR DRIVE'

LED

is on:

Determine that the command signal is zero. To

do this, remove the command signal connector. If

the LED remains on, the circuit card has likely

failed.
'SCR DRIVE'

LED

is off:

Remove the 24Vac power connector. If the load still

has power, the SSR module has probably failed.
To determine if the SSR module is shorted, remove

the line and load connections and measure the

resistance across the line and load terminals of the

controller.If the resistance is less than 10,000

ohms, the SCR module has probably failed.

If a replacement SCR module is ordered, specify

the voltage, current rating and serial number of the

controller.

Load voltage snaps on:

Determine that the primary of the circuit transformer

is connected across the same phase as the

controller and load. (See figure 6 on page 6.)

NO LOAD POWER:

The 'LOAD CURRENT'

LED

is not on, the

intensity of the 'SCR DRIVE'

LED

can be varied:

Determine that the load is wired correctly to the

controller. Determine that all fuses are “OK”. If the

voltage across the SCR module is equal to the line

voltage, the SCR module has probably failed.
If a replacement SCR module is ordered, specify

the voltage, current rating and serial number of the

failed unit.

MAXIMUM LOAD VOLTAGE CANNOT

BE REACHED:

Determine that the primary of the circuit transformer

is connected across the same supply as the

controller and load.
This problem could be caused by the primary being

connected across the load and line connection at

the controller, or across a different phase than the

controller and load. (Fig. 6 on P. 6.)
The current limit feature may prevent maximum line

voltage from being applied to the load. To determine

if the current limit feature is preventing full voltage

from being applied to the load, rotate the

potentiometer labeled "LIMIT" 1 turn counter-

clockwise. If the load voltage decreases, the load

current is being limited.

THE FOLLOWING ARE SYMPTOMS

AND POSSIBLE SOLUTIONS:

'LOAD

CURRENT'

LED

'SSR

DRIVE'

LED

COMMAND

SIGNAL

CONNECTOR

24 Vac

CONNECTOR

5 CCW W CW

Figure 8. 1032 Board Layout.

ZERO

SPAN

LIMIT

Advertising