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2.2.3
After Testing
On completion of the test, switch off the output using the “off” pushbutton. Return the output
control to zero and switch off the supply. Before disconnecting the test object ensure the
mains supply switch is in the OFF position.
2.3
Timing System
The PCU1 timing system is closely integrated with the main output and is very flexible. A
summary of the start and stop events for the timer is shown in the table below.
Timer Mode
Timer Start
Condition
Timer Stop
Condition
Automatic
output off
Example
application
Off
-
-
-
Set current
Internal Start
Main output on
Contact set 1
change
When timer
stops
IDMT relay
Single Contact
using
Contact 1
C1 1st change
C1 2nd change
C1 1st change
(timer start)
Auto-recloser
Single Contact
using Contact 2
C2 1st change
C2 2nd change
C2 2nd change
(timer stop)
Drop-off timing
Dual Contact
1st change C1
C1 change
C2 change
C2 change
(timer stop)
Dual Contact
1st change C2
C2 change
C1 change
C2 change
(timer start)
Auto-reclose
relay
Current
Operated
Current >20% of
selected
metering range
Current < 20%
of selected
metering range
Current <20%
Timer stop
Miniature circuit
breakers
Pulse 0.2s
Main output on
Time = 0.2s
200ms
Set current for
thermal devices
Pulse 0.5s
Main output on
Time = 0.5s
500ms
Pulse 1s
Main output on
Time = 1s
1s
Pulse 2s
Main output on
Time = 2s
2s
The timer resets automatically when the output “on” pushbutton is pressed. In each mode that
the timer is active, the output of the unit must be switched on to arm the timer.
Each contact channel has a contact input for volt-free contacts and a Vdc input for dc
voltages. The Vdc input may be used to trigger the timer from a dc voltage, and will trigger
from either the voltage switching from zero to 24-240Vdc or 24-240Vdc to zero. The voltage
must be connected with positive to the red “Vdc” terminal and negative to the blue “com”
terminal.
