Electrical Connection; What To Do In Case Of Gas Accumulation - COMEM Buchholz Relays Manual De Instrucciones

Electrical connection

CAUTION
The operating and installation requirements described in this
manual must be strictly followed. If not, the device can be
damaged or a malfunction may occur.
WARNING
Dangerous electrical voltages!
It is imperative to deactivate the power supply during the wiring
of the device.
CAUTION
During the terminal box assembly, use caution not to damage
the gasket. If this occurs it must be substituted.
If you do not use all the 2 cable glands pay attention to close the
free cable gland with a plug or gasket.
Multicore signal leads can be fitted in the Buchholz relay
through cable glands (M25x1.5 – Fig.C/1). A conductor
cross section of 1.5 mm
(4x1mm o 6x1mm shielded twisted pair cable for ana-
2 2
log/digital output). The maximum cross section that can
be clamped is 2.5 mm .
2
Proceed with the following instructions:
• Unscrew the 5 un-losable M5 screws M5 (Fig. C/1)
• Remove the cap (Fig. C/2)
• Insert the lead through the cable gland (Fig. C/3)
• Connect the lead to the terminal board (Fig. C/4)
according to the chosen electrical scheme (tab.1)
Figure C
6
(copper) is recommended
2
Scheme Alarm
(4)
contact
A NO
(1)
L C.O.
(3)
P n. 2 NO
G NO
I n. 2 NO
V n. 2 NC
(1) NO: normal open contact; (2) NC: normal closed contact; (3) C.O.: change
over contact; (4) For other specific electrical scheme please contact Comem
(e-mail : customerservice@it.comem.com)
Table 1
Pneumatic testing by pneumatic valve
This is performed by injecting air using a pump (furnished by
COMEM on request as an accessory kit) causing the oil level
inside the BR to drop down and actuate the alarm float.
Proceed as follows when using the kit:
• Remove plug (Fig. D/2), screw valve (Fig. D/3) and
relative nipple on relay valve (Fig. H/1)
• Remove cap (Fig. D/4), insert pump (Fig. D/5) using the
threaded connection and turn the lever to OFF, inject air
as necessary to activate internal mechanisms.
• To restore the oil level and simultaneously bleed out
internal air remove plug (Fig. D/7) and open ball cock
(Fig. D/6).
• After these procedures close cock (Fig. D/6) and plug
(Fig. D/7), remove pump (Fig. D/5) and relative
accessories (D/3) and (Fig. D/4) and close valve (Fig.
D/1) using plug (Fig. D/2).
1
4
3
2
7
3
6
2
Figure D
What to do in case of
gas accumulation
In case of alarm, the gas should be checked immediately
to determine the cause of the fault and avoid additional
damages. To this end, withdraw the gas from the BR and
analyze it. For gas sampling and transport it is recommen-
ded to use the "Gas Sampling device" supplied by COMEM
(see Appendix A).
BUCHHOLZ RELAYS
Alarm Trip
terminals contact
3-4 NO
NO : 4-C2 C.O.
NC : 3 - C2
C2-3 NO
C1-4
3-4 n. 2 NO
5-6 n. 2 NO
7-8
5-6 n. 2 NC
(2)
7-8
4
1
7
Trip
terminals
1-2
NO : 2-C1
NC : 1-C1
1-2
C2-2
C1-1
1-2
3-4
1-2
(2)
3-4
5