66kV Riser Pole Arrestors

[Redpath]

We are converting a 1200m section of overhead 66kV to underground (3 x 1C 630mm² CU XLPE). Looking for suitable 66kV Riser Pole polymer arrestors to install at both pole top ends. Can anybody help.

 

[alehman]

These are very common products. Is there something unusual about your situation?

Try Cooper, Hubbell or ABB.

Alan
“The engineer's first problem in any design situation is to discover what the problem really is.” Unk.

 

[jghrist]

I don't know that riser pole arresters are available at that high a voltage. They are normally for distribution. I think an intermediate class or station class arrester would be suitable (these are ANSI classifications).

 

[alehman]

Good point. "Riser pole" style quit at 36kV. I guess I was thinking station type being mounted on the riser pole.

Alan
“The engineer's first problem in any design situation is to discover what the problem really is.” Unk.

 

[WindTurbinesAreFine]

You could make special crossarms for your riser pole so you could install station mount arrestors.

 

[busbar]

Pacific Gas & Electric in some places has used station-class arresters on riser poles in areas of very-high lightning incidence. My understanding is that the brackets they use in this application are made by Aluma-Form.

 

[busbar]

See

http://www.alumaform.com/equipment_mount.pdf

 

[Redpath]

Thanks for all the feedback todate.
Thoughts so far:
With nominal Line to Line Voltage of 66.0kV rms.
Typical Max line to Line Voltage of 72kV rms.
Max Line to Ground Voltage 41.6kV rms (On 3 phase systems the line to ground voltage is divided by 1.73).
We have determined how high the line to ground voltage of the unfaulted phases will rise to during a ground fault.
We have also calculated Potential System Over voltages.

Since Riser Pole Arrestors quit at 36kV we are looking at installing 72kV Intermediate class arrestors with an MCOV of 57.0.
Comments would be apprieciated.

 

[alehman]

What's your calculated maximum line-to-ground voltage?

Alan
“The engineer's first problem in any design situation is to discover what the problem really is.” Unk.

 

[Redpath]

Max Line to Ground Voltage as stated above

 

[alehman]

You could probably use 60/48kV.

Alan
“The engineer's first problem in any design situation is to discover what the problem really is.” Unk.

 

[stevenal]

MCOV=42 kV unless the TOV is insufficient.