CSA Rules and Level Control of Submersible Electric Pumps

Hi I can answer your question but first I need to ask a few.

What is CSA?

You refer to "Arc Flash rules" I guess you mean for electrical equipment in a mine.?

What height of fluid above the pumps and as I guess you are pumping water, are you pumping to the surface to a tank?

Just on what you have said you can have level control with no worries of arcing if a VSD is used, and with the correct level control equipment it will work without supervision

Brich,

CSA is Canadian Standards Association, similar to the Yankee UL.

I supposed there would be the possibility of an arc flash, if there were a problem with the disconnect or control panel, creating an arc flash when the pump automatically started and involving an electrician testing the live panel.

Ok, you can either install a pressure sensor at the bottom of the pump that would tell you how high the fluid is above the pump or an Ex (explosion proof) electronic level switch in the tank(?) (still not sure of the final application) and connect either one or both to a Variable Speed Drive, the signal from the pressure sensor or level switch will tell the VSD to speed up or down, no moving parts, that is, contacts that could arc.

This is something I would look at, but I am making a few assumptions. Do you have a control room that you would put control equipment in if the equipment is to be used underground? Is it positive pressure? Do you use Ex equipment? Let me know

VSD's are not a viable option here, an open pit mine, where these (portable) pumps remove surface water to large impoundments.

My question centers around whether or not CSA allows any sort of automatic control, to include stator thermal or electrical overload automatic reset.

VSD's are out, that leaves only electronic level controllers. As to the exact usage of equipment, as its an open cast mine, hopefully there should not be a problem, however I am speaking from experience in the UK using Ex rated equipment.

I suggest you contact the relevant authority for exact directions and the precise regulations.

Sorry I could not help further

Interesting comment. I have done several applications using float switches for level control of pumps in Canada at waste water stations. The only CSA rules we had to follow were based on Intrinsic Safety. They did not say anything about automatic level control. I do know MSHA here is the USA is more strict than UL. It may be the same in Canada when dealing with mines. I would check with CSA to verfiy that what you were told is correct.

James,

Getting info from CSA is like having your teeth pulled by a Hollywood Dentist (expensive), That is why I thought I would ask you guys first.

if you have $80 then follow this link to the CSA web site for the handbook in the use of electricity in mines

http://www.shopcsa.ca/onlinestore/GetCatalogItemDetails.asp?mat=000000000002413542

hope this helps

The way it was explained to me,

Scenario:

1. Pump with built-in level control has stopped.
2. Electrician defeats the door interlock on the disconnect located on shore to check for power.
3. While he is checking with his meter probes, pump automatically starts.
4. For some reason, disconnect is defective and arc flash occurs.
5. Electrician, lacking required PPE, is toasted to a golden brown.

This is an above ground surface mine, not requiring EX or intrinsically safe barriers.

It may be that self contained, built-in level control or even auto-reset thermal cut-out is not allowed.

I am going to spend the $80.00 (US) to find out.

Based on the above comments, it sounds like your customer was really talking about CAN/CSA Z462. This is CSA's newly published counterpart to NFPA 70E.

I think the fellow you were talking to had his ducks all out of line. This is not a mine safety issue.

As to that $80 bucks... save it. You can buy a copy of the M421 mine safety standard, but there will be no reference to control of sump pumps, manual or automatic, in that document.

CSA publishes many standards and with respect to this issue, two of those standards come to mind. The first one being CAN/CSA C22.x "The Canadian Electrical Code and the second one is CAN/CSA M421 "Use of Electricity in Mines". Neither of those standards includes a prohibition such as what you mention.

It is also possible that the prohibition is to be found in one of the numerous product standards that CSA publishes.

What I would suggest is... go back to the person who mentioned the "CSA" angle to you and ask him... "Which particular CSA standard are you referring to?".

Hey North,

Finally got a real Canadian in on this!

There has been mention of the new arc flash standard (CSA Z462) as related to this.

As my outfit is CSA certified, I have put this question to one of their electrical experts.

I found out being certified does not mean you get the standards free.

Thanks.

I sit on several code committees for the Canadian Electrical Code (CAN/CSA C22.1 & C22.2) and through my employer, I am a "sustaining" member of CSA and can get "committee copies" of all of the electrical standards and most of the non-electrical ones for my personal use.

As per any "intellectual propery organization", CSA does not give away its products to anyone. A common practice in the standards game. NFPA does not give away there work either.

I took a look through the other CSA standards and the only one that fits your bill is the Z462 standard.

This issue is more or less political in nature, as I was attempting to resolve the mines problems concerning excessive wear and wasted power, due to continuous running after pump-down, and, at the same time, promote our product.

It is difficult to be argumentative with the guy in charge of the mines electrical division, so I hesitate to confront him with this.

Our pumps are CSA approved, including built-in level control, but the mine electrician has a valid point concerning arc-flash.

The scope of most published material concerning arc flash, is that equipment should not be tested live and if it is necessary to test live, it should be done with the proper PPE.

I could interlock (electrically) the pump's internal control through a pilot cable, but that would involve additional components such as aux. switches in the disconnect.

Then this system would have to approved.

This would prevent automatic start, but would limit testing to a check for power only.

To check current, you would have to defeat the interlock, bringing the possibility of arc-flash back into the picture.

Taking all this into consideration, it appears there will always be a possibility for arc-flash, as long as a panel is energized.