Feeding
What is the nominal voltage used on our classic AC Traction system?
25,000V (25kV)
What is the preferred method of supporting 1 line / road of OLE equipment?
Single track cantilever
What conductor connects the pantograph to the overhead line system?
Contact Wire
What is the insulator on top of a sub-station called?
Roof Bushing
4.7m is the nominal contact wire height?
True
What is the supply voltage from the DNO?
132,000 (132kV)
On multi-track areas, what are the support arrangements used?
Portals and Headspans
What prevents energised overhead from connecting to the general mass of earth?
Insulators
What is the term used for a connection between a cable and a bare conductor?
Sealing End
5.7m is the minimum wire height at a level crossing
False
(5.6m)
What are the supply voltages from the TNO?
275,000 (275kV)
400,000 (400kV)
What is the diagonal tube on a canti-lever called?
A Strut
How is a bare feeder denoted on site?
Yellow Triangles
What connects the contact wire to the cantilever?
Registration Arm
The maximum wire height at a level crossing is 5.94m.
True
What is the nominal voltage to the OLE in an Auto Transformer system?
25,000 (25kV)
Which side of the double pole disconnector does the return current busbar connect to?
Neutral Side
What is the purpose of a dropper?
To support the contact wire from the catenary.
What connects the aerial riser to the catenary wire?
A switch
ATF stands for Auto Transformer Feed.
False
It stands for Auto Transformer Feeder
What is the voltage generated at source before distribution?
22,000V (22kV)
If this moment is exceeded the mast will lean and the mechanical integrity will be compromised.
Overturning Moment
What is the term used for OLE without auto tension?
Fixed equipment / termination
What bond connects the traction return rail to the return conductor?
Mid point connection (MPC)
The autotransformer is wound such that there are two 25kV outputs from a common transformer winding - one 25kV positive and one 25kV negative half-cycle at the same instant, which is occurring 190 degrees out of phase with each other
False
180 degrees out of phase