ABB Modures LZ92-1 - PRE-COMMISSIONING SETTING VERIFICATION; RELAY INSERTION AND POWER-UP

6. COMMISSIONING
6.1 Checking the settings prior to commissioning
Before commissioning the relay, that is before the protected unit is energised,
it is necessary to:
- perform all the checks according to Sections 4 to 5.7
- set the relay as described in Section 3.
6.2 Inserting the relay and switching on the auxiliary supply
It is only permissible to insert or withdraw the plug-in units with the
auxiliary supply switched off!
Care must be taken that each plug-in unit is inserted in its designated posi-
tion in the equipment rack. Insert the respective unit carefully with the
withdrawing handle horizontal until resistance is felt. Now raise the withdraw-
ing handle, which acts as a lever to complete the insertion of the relay, to
the vertical position and push it fully home ensuring that it latches securely.
A unit is correctly inserted, if the hinged flaps at the front top and bottom
edges of the rack can be lowered, respectively raised, without difficulty.
It is only permissible to switch on the auxiliary supply after all the units
have been inserted.
6. 3 •rest points on the unit EW91
30
The most important signals are available for measurement at ten respectively
twelve sockets (see Section 3.12) on the front of the input transformer unit
EW91. 'l'hese signal outputs are short-circuit-proof, but on no account should
they be used for injecting singals. The inner diameter of the sockets is 2 mm
and a normal multi-meter may be used for measurement, providing its internal
resistance on the range being used is greater than 1 MOhm.
The following signals and quantities are available at the sockets:
0
Bl
-o/o-
Common zero for measuring the voltages at all the other sockets
(clean supply 0 V).
Blocking signal. The normal voltage at this socket is 10 V, but
when the relay is blocked by either the auxiliary supply
monitoring circuit or an external blocking signal the voltage
falls to 5: +2 v.
Tripping signal. This socket is at +10 V whilst the relay is
emitting a tripping signal to the circuit-breaker. The signal
is tapped off just before the auxiliary tripping relay and thus
appears 2 to 5 ms before the tripping contact actually closes.