PR S 40011 Flashcards
Renewals work
What must be completed before restored equipment is brought back into service
it must be tested and certified correct
what is a like for like
the replacement of an item with and exactly identical item, or deemed acceptable by a signal engineer
What is the purpose of the like for like renewals process
to mitigate risks associated with the renewal of equipment
what must licensed signalling personnel ensure when certifying renewals
the equipment renewed is of the correct type and configuration and no alteration to design has occurred
Do you need a commissioning engineer for a like for like renewal
No
When needs to happen if the item being replaced isn’t an exact identical replacement
Authorisation must be sought from the maintenance signal engineer or signal engineer in charge of the works to proceed under a like for like process.
What documentation is required for general renewals work
Authorised design, works package, work instructions, test plan
Can plug in relays be changed in-between trains
Yes
What must be done prior to placing relays into service
it must be visually inspected for damage. Configuration check of the same voltage, type, contact configuration and pin coding.
What must be done for magnetically latched relays before being placed into service
They must be driven down
What level of importance is the replacement of shelf type relays classified as
safety-critical
Can someone take over midway during a shelf relay replacement
No, it is not permitted
What value must be tested when replacing a shelf relay
Shunt value, local and control track coil voltages are correct.
precautions applied to the renewal of electrical signalling apparatus
-new equipment is inspected and tested to be correct type and order
-contacts to be changed over one at a time
-the renewal of mechanical equipment doesn’t affect operation
-all adjustments made beyond specified limits are approved by a signal engineer
-all adjusted equipment tested in situ
What needs to be checked when a transformer is changed and when
polarity is tested before and after the change
what must be done before the disconnection of wiring or removal of equipment
The wiring is to be correlated
what must happen with de-commissioned or yet to be commissioned equipment
de-commissioned equipment must be disconnected from use. new wires unconnected until officially commissioned. exposed wires insulated, secured and labelled.
What must happen before disconnections or connections
the circuit is to be booked out of use
what should happen with spare wires
Terminated on spare terminals in racks. Track side apparatus shall have the ends insulated if there are no spare terminals.
What must happen with equipment not in use
it must be disconnected from the interlocking, open circuited and labelled
Can you use adhesive devices to insulate prepared wiring
no, as it can leave residue causing unreliable contact resistance
are test lamps allowed to be used
no, they can provide a significant earth leakage path.
Who must be consulted if a specific work instruction is not provided
The signal engineer for the works
Some examples where a like for like is not applicable and authorisation is required
-a trainstop with closed contacts replaces one with open contacts
-shelf replaced with a plug in conversion
-newer version of point machine replaces an earlier version