Variac or not?

[peverett]

I use a variac to bring up re-capped items for the first time. This, as mentioned above, helps isolate inadvertant shorts, etc.

Luckily, the variacs that I have are coupled with an isolation transformer and have both current and voltage meters. This makes it safer to bring up hot chassis sets and makes it easier to spot trouble.

These particular variac systems are identical Heathkits. I built one myself years ago and purchased the other already assembled.

[jeyurkon]

Originally Posted by peverett

I use a variac to bring up re-capped items for the first time. This, as mentioned above, helps isolate inadvertant shorts, etc.

Luckily, the variacs that I have are coupled with an isolation transformer and have both current and voltage meters. This makes it safer to bring up hot chassis sets and makes it easier to spot trouble.

These particular variac systems are identical Heathkits. I built one myself years ago and purchased the other already assembled.

I have an isolation transformer and I just purchased a new variac. I was curious to see if a watt-miser would work at reduced voltage. It didn't. I saw a brief flicker in the display, I guess it needs to come up cleanly.

I kept increasing the variac to 120VAC when the lights went out. The watt-miser has surge protection built in. 120 on the dial of this new variac turns out to be 140VAC at the output. It has a built in voltmeter and when it reads 120VAC the output is actually 130VAC.

The surge protector just did it's job and tripped a circuit breaker. The watt-miser is o.k. I was hoping to monitor power with it as I brought things up. Guess I'll go back to the trusty ammeter.

John