1 Phase Padmounted Transformers

[davidt]

I am trying to get a feel for an industry practice.

When companies install 1 phase padmounted (PM) transformers on fiberglass pads do thet bolt or other wise secure the transfomer to the pad?

At the company I am working with, the standards do not specify securing the transformer to the pad. They used to secure the transformers years ago, but found that when the PMs were struck the pads were often cracked or otherwise damaged. We would like to go back to securing PMs to pads, because we believe that hazards are created when PMs are knocked off pads. We would like to know what most in the industry do.

Tom

[topgroove]

we secure the padmount to encloser with the metal brackets and two bolts. if you look at the encloser you'll notice some holes with threaded steel inserts.its not gonna stop the padmount from sliding off if its hit with enough force.

[A Laska Lineman]

You should always bolt down a single phase xmer. The xmer could move or slide when parking elbows(isolating). In cold weather ice is formed through condensation from heat (depending on load) and changing weather conditions. A single phase xmer only ways aout 600lbs and can be moved easily by hand, especially on fiberglass. When pulling an elbow off an older installation the silicon that should have been applied has a tendancy to dry up a little, plus the suction that it creates, makes it harder to remove. I have seen 4 Linemen try to pull off an elbow with no success. Thank goodness it was bolted down. When pulling off or pushing on an energized elbow, it could create a very hazardous situation if the xmer is not bolted down. The price of a new fiberglass pad is minimal compared to the hazards you would be exposed to by a xmer not properly secured. If xmers are placed in a high traffic area add gaurd posts to protect the equipment or re-engineer it to be moved to a less exposed area.

[49pan]

The standard in Fl is to bolt the TX down. It not only helps if a car bumps it, the extra Wt. of the pad helps keep in place during the Hurricanes. We use concrete pads.

[LEAFMAN]

Where i am from we do not bolt down our padmount transformers. The odd one gets hit by a vehicle but we don't have any major issues. They are also mounted on concrete pads.

[Patriot]

We use either half depth or full depth, fiberglass vaults under our single phase padmounts, and they are bolted down either with the flange or through a hole in the transfomer base into the tapper vault holes. We have to bolt them down because of the 35 kv large interface elbows, it takes two men and boy to pull them off!

[graybeard]

We use the fiberglass valts and bolt them down. Like they said it can take 2 men and a boy to pull elbows.

[Squizzy]

There was an accident about 10 or so years ago when a guy was digging alongside a new padmount transformer. He dug too far down and the concrete pad "fell" into the trench he would of been right if the transformer had of been bolted down but it slid on the pad an crushed him to death. Could have been prevented for the sake of $10 worth of dynabolts. I turned up to make off the cables and put some lights in the switchroom only top be turned around by the firemen as they were lifting the transformer. The padmounts now sit on a galvanised or concrete frame that sits about a meter and a half in the ground so cables can be run into the transformer or switch without fear of a repeat...

[CHICAGO HAND.]

we bolt them down so we dont drag them around the back yards trying to switch in them.

[PA BEN]

A picture is worth a 1000 words:D
http://i154.photobucket.com/albums/s276/PABEN07/PICT4781.jpg

[hosmerunited]

nice picture. is that a fiberglass padmount? in the area that i work in alberta installing urd.(we install everything from just power to phone, tv, and even getting into gas.) we have been using concrete pads and we bolt them down with the 4 bolt holes that are provided in it. while talking to one of the journeymen's at work he has said that the fiberglass pad mounts where in use in someparts of alberta and in saskatchewan. although he didnot know if they where still being used though.
mike

[PA BEN]

http://i154.photobucket.com/albums/s276/PABEN07/PICT4782.jpg

[loadbreak55]

We haven't used that type of pad for years.All of our tubs set on a fiberglass coffin.We started this so we could leave enough wire in the bottom to re-terminate if an elbow fails without having to splice the conducter.Work's great!It also stops the "radical"bending of the conducter,that can cause premature failure.:)

[PA BEN]

Look at the picture on page one, we use a cement vault and lay extra wire in the bottom.

[graybeard]

We used to use the poly pads too. Thankfully we went to the fiberglass basements or coffins some years ago for the same reason, so you can have extra wire in case you need it. Been trying to talk managment to let us use pgravel in the bottom to keep the critters out.

[playtime]

Hey PA, Put that bolt through a square washer first and you'll get a little more holding power on that flange of the transformer. Works well.

[sedm]

from la dept of water & power, we bolt down all our surface pads & switch gear. we have had problems with people getting into ourpads & stealing the cable. you would be suprised how lucky some of these people are not to get burnt or killed. plus it keeps them from sliding during earth quakes. all pad tops are cement