Vibration Isolation Pad need no bolting?

[Kannox]

Our electrician just completed all scopes of work and all works fine. What is bothering me is that they have laid down the new transformer on some rubber block thing that they call a vibration isolator without bolting on the cement pad. They have said that there is no need to bolt the transformer when laid on that rubber pad. We have a few old transformers without that rubber pad but they are bolted on cement padding. I get the idea but is this normal and meets the compliance these days or still need to be bolted-on cement padding through the isolator? Thank you.

 

[infinity]

We never bolted down transformers set on rubber isolation pads. IMO unless there is a seismic requirement I don't see it as an issue.

 

[zbang]

Transformers seldom move on their own- gravity and friction hold them in place quite well (except for seismically active areas or otherwise where there's a lot of vibration). Older ones might have been bolted down as part of the build spec. That said, the environment and location matter; heavy industry vs office park or Wichita KS vs San Francisco bay area CA (which has multiple seismic active faults).

As a comparison, how many people bolt down a file cabinet fill of paper?

 

[GoldDigger]

Among other things, many people would have a hard time figuring out how to bolt the transformer to the pad without defeating the vibration isolation feature.

 

[infinity]

I agree with zbang since most transformers are very heavy gravity will keep them in place. If mounting and vibration control are an issue you can always use a spring isolation system which is mounted to the floor. We've used these when they were part of the spec.

 

[tom baker]

And I have see vibration isolation pads for air compressors that bolt to floor and air compressor feet

 

[hillbilly1]

And I have see vibration isolation pads for air compressors that bolt to floor and air compressor feet

The last couple of compressors I installed specifically said not to bolt them down. A couple of 10 hp piston models, and a large air screw on a tank.

 

[zbang]

Most air compressors tend to vibrate a lot more than transformers; something about all the moving parts.

 

[mtnelect]

California is certainly earthquake country ... But that is certainly not necessary. On the other hand, how about an air compressor mounted on a wooden palette ?

 

[Eddie702]

You could put anchors in the concrete and run threaded rod up through the rubber pads and put nylon lock nuts on the rod and leave them a couple of turns loose. Or use isolators as shown above.

Mason makes all kinds of isolators and seismic stuff