Power Conditioner

[George Stolz]

I am currently working in a vet hospital. They are remodeling a radiation-shielding room to install a very intricate machine. To be honest, I'm not rightly sure what this machine even does, but I know it bears a multi-million dollar price tag, and has several rooms and it's own cooling system to it's credit.

The great thing about this one is not only do we have the usual architectural vs. electrical drawing conflicts, but the machine installation manual (all 82 pages of it) also makes specifications for locations and wiring of the peripheral components of the system, such as two systems of cameras, different sets of lights, warning signs, etc - so keeping things straight is exceedingly difficult.

We muddle through for the most part.

At any rate, we're installing EMT for the various components of the system, and I'm trying to figure out what the scam is with one item called a "power conditioner (transector)". Judging from what I am seeing, it appears that this thing is a transformer - but the thing is, no grounding connections are indicated on the plans, or disconnecting means, or anything.

It's difficult even saying for certain where power is headed - but it appears that this thing takes in 480V, and kicks out 'conditioned' 480V as well as 208V. Does this sound right?

 

[mdshunk]

A transector type transformer normally also has capacitors inside. Have you checked the manufacturer's website? http://www.transtector.com/power.htm

 

[George Stolz]

Marc, that is exactly what I needed, I've got the manual now!

Now I'll try to figure out what it does, and how I install it.

 

[George Stolz]

Okay, now I get it, thanks Marc.

Now, a follow-up question: this 1625 pound cabinet is to be placed on a strut rack that a strut contractor is going to build next week. There is a pit approximately five or six feet in front of the proposed location for the rack.

The rack is going to be built 5' 6" A.F.F.

Any ideas on how to lift this thing into position in such cramped quarters?

 

[iwire]

A chain fall is usually our method if we can not get in a forklift of some sort.

That said depending on job conditions at 1600 lbs we might just hire riggers to do the work, they have the right equipment and skill.

 

[mdshunk]

Any ideas on how to lift this thing into position in such cramped quarters?

Little Mule/Coffing hoist. Most of the bigger xfmrs have lifting eyes or provisions to install lifting eyes.

 

[brian john]

George:

I have always contracted a rigger, now two issues here one a friend of mine owns and operates a rigging firm (just makes it easy for me). Second thing is I have seen several electricians hurt moving equipment they have IMO no business moving, another thing if the rigger drops it he owns it and they have the proper equipment to move the item in question. Lastly is a safer better use of an electricians time (not moving heavy equipment).


I would not want a rigger to make electrical connections to a generator they delivered

 

[iwire]

another thing if the rigger drops it he owns it and they have the proper equipment to move the item in question.

There is a lot to be said for that. :smile:

Many times we have heavy items dropped off at our riggers shop for storage until we need it, kind of nice to just point out where it has to get.

Last summer I had a 5600 lb transfer switch brought into an existing electric room. The riggers had to lay it down to get in the doors then stand it back up again. They made short work of it, no one or equipment damaged. It also meant our guys could keep running pipe.

 

[zbang]

In some environments, the contract may require you to hire a rigger from the facility's list for moving heavy things. If it can't be moved easily by 1 or 2 people and a dolly or forklift, I'd much rather have someone else to deal with it. (It's like moving a piano, the folk that do it every day make it look easy, but it's still up three flights of stairs..)

 

[George Stolz]

Many thanks for the suggestions.

 

[quogueelectric]

medical equipment

medical equipment

Sound like a linac machine a small linear accelerator used for particle acceleration used sometimes for inoperable brain tumors this machine can get almost anywhere and destroy the shape of the tumor with minimal collateral damage. I installed one 2 yrs ago for a large hospital in my area. Lots of controls and interlocks right up my alley.

 

[George Stolz]

That's exactly right.

I noticed the instructions called for "grounding conductors" sized to certain gauges, but was unclear whether they were referring to EGCs or supplementary GECs.

Did you install oversized EGCs per the instructions, or add an auxilliary GEC?

They made a special point to mention that they were to be connected to the "Hospital Grid System", but I honestly don't know what that means. No special grounding conductors were shown on the prints.

>Ground equipment through the "Hospital Grid System" (The equipment is sensitive to electrolysis from water pipe grounding). Do not use water supply piping for grounding!
>A grounding copper cable, minimum conductor size of not less than 2 AWG originating at the hospital main ground.

I wasn't quite sure what to make of that.

Even the power conditioner made no comment on grounding, although I believe it is in fact an SDS. What did you do?

 

[quogueelectric]

I was replacing an old xray machine

I was replacing an old xray machine

That's exactly right.

I noticed the instructions called for "grounding conductors" sized to certain gauges, but was unclear whether they were referring to EGCs or supplem
Even the power conditioner made no comment on grounding, although I believe it is in fact an SDS. What did you do?

The hardest part of this install is the trough in the floor make sure when you are forming and saw cutting that all measurements are dead on the center line marked out for the machine. This install is particularly dangerous because they will be hanging a 4 inch thick slab of lead bricks above the cieling I think I estimated the weight at 30 tons hung by by huge expansion bolts into the concrete above. There was some steel added but I just dont trust those expansion bolts to hold that much weight. Try not to get involved with the usual grounding battles with this installation it operates on different frequencies and voltages and I am sure the engineers who designed this equipment are quallified to size the grounding. Just follow the blueprints. I think the feeders for the xray generator need to be a special type of like welding cable you should check this out as this cable is very expensive. There will be a control box with relays to interconnect with the machine and the interlocks for the doors the xray in use lights and other safety interlocks. mushroom emergency off buttons this is really hurting my brain. Oh btw is this machine for BrainLab?? Make sure that you locate this relay cabinet in an easily accessable location and try to prewire asmuch as you can on the ground because you will be spending a lot of time in this relay box. Nothing fancy just good quality cform relays like potter brumfield You may have to build this your self

 

[George Stolz]

...I am sure the engineers who designed this equipment are quallified to size the grounding. Just follow the blueprints.

The engineers who designed the equipment didn't draw the prints - that's why the manual and the prints disagree, that's the problem.

I appreciate the other tips, I'll look into them.

 

[iwire]

The engineers who designed the equipment didn't draw the prints - that's why the manual and the prints disagree, that's the problem.

I appreciate the other tips, I'll look into them.

George let me suggest that you don't let your enthusiasm cloud your judgment.

As the EC your job is to wire the equipment, not design it.

Don't hesitate to use RFIs to the engineers to get answers to questions that seem basic.

We live in a litigious society, your dealing with very expensive equipment that may well be capable of doing more harm then good to the patient.

Do the right thing and don't put your company into a position of liability.

Don't get me wrong, I applaud your 'need to know' I like to know as much as I can about the equipment I wire but make sure the people that have the letters after their name make any decisions of any consequence. Or at the least send an RFI with your solution and intentions clearly stated and say unless informed otherwise you are going to proceed.

In a nut shell CYA.....cause no one else is going to.

 

[brian john]

Bob:

One of the things I try to teach all employees is never hesitate to use the phone, fax or email to contact the manufactures most are more than willing to help. Though some are difficult to reach. (PHONE TAG)

 

[RayS]

As the EC your job is to wire the equipment, not design it.

Don't hesitate to use RFIs to the engineers to get answers to questions that seem basic.

We live in a litigious society, your dealing with very expensive equipment that may well be capable of doing more harm then good to the patient.

Amen, Bob

I like to say that "someone was paid to figure this out- it's their baby"
Don't wanna make it your problem by "redesigning" it for them.

 

[quogueelectric]

startup

startup

When they first tested this animal I still had some control wiring to finish and was in the belly of the beast doing a circus act to terminate final conductors when DRIP. An unidentified liquid substance dripped on my hand OH NO! I was petrified I didnt know if this was highly radioactive liquid uranium or poison or acid. I wondered if I would ever be able to see my wife and kids again. If I needed to dilute it or contain it. I went racing for the Physicist who kind of looked like Kelly Lebrock in the movie Wierd Science but with black hair. She saw my total panic and smiled and said" its just water you are going to live" she chuckled as she walked back to work. The plumber just missed tightening a fitting took 10 years off my life.

 

[George Stolz]

Thanks, I'll ask.

 

[George Stolz]

There will be a control box with relays to interconnect with the machine and the interlocks for the doors the xray in use lights and other safety interlocks. mushroom emergency off buttons this is really hurting my brain.

I couldn't resist an update, I've been having to change things around as ASI's and such come down the pike. In the attempt to understand what the EE is asking me to do, I've been taking the schematics home and drawing them out myself as a reference, I thought I'd pass them along.