[TCML] RE: Terry Filter - adding more MOVs than required

[Lau, Gary]

Adding more than the prescribed number of MOV's is kind of like replacing a fuse or a circuit breaker with a higher current rating than is proper.  It won't "harm" the performance in that it won't diminish performance or damage any components, but it could permit an excessive voltage to occur under some fault conditions.  I _think_ that when Terry prescribed the number of MOV's for various NST voltages, he allowed for the usual 140V Variac boost, so I don't think you need to compensate for that.

Regards, Gary Lau
MA, USA

> -----Original Message-----
> From: tesla-bounces at pupman.com [mailto:tesla-bounces at pupman.com] On
> Behalf Of Stephen J. Hobley
> Sent: Friday, August 29, 2008 11:28 AM
> To: Tesla Coil Mailing List
> Subject: [TCML] Terry Filter - adding more MOVs than required
>
> Does anyone know that if I populate my Terry Filter with more MOVs than required
> (ie building a 15KV filter,and running it with a 12KV NST) would this harm the
> performance in anyway, or reduce the protection?
>
> I have a 12KV NST based system, and installed the correct number of MOVs, but
> my variac as a 120/140V switch, which I assume runs the NST to 14KV at the 140V
> position.
>
> Would it be safer to install more MOVs?
>
> Steve