NOTE : Please note that for the operational safety, RAISE and LOWER relays are
interlocked and hence OLTC will never receive two opposite commands
simultaneously.
13. UNDER VOLTAGE OPERATION CHECK :
Reduce PT Supply below 88V (atleast 87.5V) (UV is factory set at 80% of the
Nominal voltage), UV/OV lamp will turn-on immediatelly. (Under this condition R
lamp will also be on) but the Raise control is inhibited. Note that between
Blocking & Release (Restoration), a hysteresis of 5% has been provided. Check
the UV contacts on pins 13 & 14 of the Rear Panel Teminal Block.
Raise the PT Supply above 94V, UV/OV lamp should turn off immediately.
'R' lamp indication however shall remain on, if the PT voltage is still below the
Raise setting. The raise control pulse comes on after the set time delay.
Disconnect external PT supply the UV/OV & Rlamp will turn on immediatelly.
The UV/OV relay will operate. After restoration of PT supply, the lamp will turn 'off'
& UV/OV relay will be deenergised.
NOTE : Blocking (80%) & Restoration (85%) are factory set values, unless the customer
has specified other values.
14. OVER VOLTAGE OPERATION CHECK :
Increase PT Supply above 132V (atleast 132.5V), UV/OV lamp will turn-on
immediatelly.(Under this condition L lamp will also be on) but the Lower control is
inhibited. Note that between Blocking & Release (Restoration), a hysteresis of
5V has been provided. Check the UV/OV contacts on pins 13 & 14 of the Rear
Panel Teminal Block.
Decrease the PT Supply below 127V, UV/OV lamp should turn off immediatelly.
'L' lamp indication however shall remain on, if the PT voltage is still above the
Lower setting. The lower control pulse comes on after the set time delay.
NOTE: Blocking (132V) & Restoration (127V) are factory set values, unless the
customer has specified other values.
15. CONTROL FAIL ALARM RELAY :
Change the PT voltage to get either R or L indication. Keep the regulated voltage
outside the set dead band. After 15 minutes (approx. ). the control fail alarm relay
will operate and will remain in energised condition till the voltage returns to set
dead band. This operation will be indicated by red LED marked CF mounted on
front panel of AVR Relay. The relay contacts can be checked on Pins 15 & 16 of
the Terminal Block.
Take the regulated voltage within set dead band. The control fail Relay will get
deenergised and the contacts on Pins 15 & 16 will open and CF LED
will stop glowing. Similarly this operation can be checked by taking regulated
voltage on other side of set dead band
6
To Next Page
Loading...