13
251/02 en
4 Parametering
DELAY T2
10s
(PERM,1-10s,OFF)
06/30
H/T Pulse duration (option)
The value designated as "H/L pulse duration“ is the time
interval occurring between two pulses during high-speed
return control. The adjusting range is between 0 and 10 s at
an increment of 0.1 s each.
The value parameterised in "H/T pulse duration“ is used both
for the 'on’ time and the 'off’ time of a switching operation,
i. e. for an adjusting value of "2 s“, the relay will be switched
on for 2 seconds, and then remains switched off for another
2 seconds. That way a new switching operation cannot be
initiated until after 4 seconds.
Here, the make time is identified as "n –> 1" or "1 –> n", and
the break time is identified as "MOTOR RUNNING“ in the
third display line.
H/T PULSE DURATION
0.5 s
(0.0 s - 10.0 s)
27/30
4.5
Setting the overvoltage detection (U>)
with automatic return control
The response threshold can be set from 101 % to 130 % of
the desired voltage level in steps of 1 % by pressing the SET
and
function keys.
In the event of an overvoltage detection response, the on-
load tap-changer is operated by periodic pulses to the
motor-drive until the overvoltage falls below the response
threshold. The motor-drive is controlled by periodic pulses of
1.5 s through the "Lower“ output relay while the set delay
time re-mains inactive during this operation. At the same
time the alarm signalling LED lamp "U>" responds and a
signalling relay is energized (contacts 24/25/55) as long as
overvoltage is present. If the voltage regulator regulates
towards a higher voltage than the set limit U> due to an
unfavourable parametering (e.g. too high LDC settings), it is
prevented from exceeding the limit. This condition is
signalled by the signalling relay for ‘function monitoring’,
after 15 minutes.
4.6
Setting the undervoltage blocking (U<)
The response threshold for undervoltage blocking can be set
from 70 % to 99 % of the desired voltage level in steps of
1 % by pressing the function keys Set and
.
Undervoltage blocking prevents tap change operations in the
event of a network breakdown. The voltage regulator output
pulses are blocked and the alarm signalling LED lamp "U<"
and a signalling relay (contacts 22/23/56) respond when the
measuring voltage falls below the set blocking value. After a
delay time of approx. 10 s, the associated signalling relay is
energized and remains that way. The signalling relay does
not respond in case of a failure of the measuring-circuit
voltage or supply voltage (< 30 V).
OVERVOLTAGE U>
105%
(101%-130%)
07/30
UNDERVOLTAGE U<
70%
(70%- 99%)
08/30
Delay time T2
The delay time T2 will become effective only if more than one
tap change is required for reduction of the control deviation
below the bandwidth limit. The set delay time T2 is then valid
for all consecutive output pulses.
Set the delay time T2 for a range of 1.0 … 10 s by pressing
the SET and
function keys.
If the voltage regulator is set to PERM, it will emit a
continuous signal. If it is set to OFF, the delay time T2 will be
deactivated.