Step up transformer confusion

[warkan]

Hey guys,

I am pretty new to this field. We have a underground armored cable laid out for around 1.5KM -2KM from the plant(Power room) to a river pond. The job of the river pump is to pump water to our plant. There are two pumps rated around 60HP each. Only, one will be run at any time. The other is just for standby. Recently, we have been having a lot of problems with the cable such as shorting and burns. Temporary fixes are not helping the case. When we checked for voltage being received in the river panel, it was around 390V instead of 420-440V. So, I am wondering if the voltage drop is the reason for the cable problems. If it is, what rated step up transformer do I install in order to regulate the voltage back to normal ? What are the criteria I need to follow ? Any help is much appreciated.

Regards,
Warkan

 

[Silly Sausage]

I very much doubt that it is in a 2Km trench,it will be dragged across the wilderness.....................

The OP better not publicise his exact location, Tidyboiler will be having away with that cable

 

[Engineer54]

I very much doubt that it is in a 2Km trench,it will be dragged across the wilderness,and in fairness to the OP,in territories such as his,cable selection comes down to what the supplier has,right or wrong. I have just calculated roughly that it is woefully inadequate for the task...options are 1) use cable as "control" for stand-alone engine driven pump.....2) use cable to provide mediocre lighting on site....so you can terminate the proper cable in the dark!

Time to start thinking about a parallel cable supply, to keep down the size and cost of the cable. I suppose he could always run another 4 core 50mm cable in, but i wondering how much damage has already been done to the existing cable....

 

[Deleted member 72666]

Time to start thinking about a parallel cable supply, to keep down the size and cost of the cable. I suppose he could always run another 4 core 50mm cable in, but i wondering how much damage has already been done to the existing cable....

It still wouldn't be big enough, not by a long chalk!

 

[Deleted member 72666]

Hey guys,

I am pretty new to this field. We have a underground armored cable laid out for around 1.5KM -2KM from the plant(Power room) to a river pond. The job of the river pump is to pump water to our plant. There are two pumps rated around 60HP each. Only, one will be run at any time. The other is just for standby. Recently, we have been having a lot of problems with the cable such as shorting and burns. Temporary fixes are not helping the case. When we checked for voltage being received in the river panel, it was around 390V instead of 420-440V. So, I am wondering if the voltage drop is the reason for the cable problems. If it is, what rated step up transformer do I install in order to regulate the voltage back to normal ? What are the criteria I need to follow ? Any help is much appreciated.

Regards,
Warkan

Hi Warkan
What do you mean by shorting and burns and what temp. fixes have you been doing?

 

[trev]

Warkan, why don't you get your electrician to come on for a chat?
It could be fun.

 

[Knobhead]

Time to start thinking about a parallel cable supply, to keep down the size and cost of the cable. I suppose he could always run another 4 core 50mm cable in, but i wondering how much damage has already been done to the existing cable....

I make it he'll need another 12Km of 50mm. I've run three cables in parallel, never seven.

If the OP has a boss I'd like to be a fly on the wall when he tells him. Or see how far he can drop kick his so called electrician. One of them will be looking for a new job. I think it's going to be the OP. I go on an international site quite often, its great how they shift the blame on to someone else.


One of the best laughs we've had in a while.

 

[Silly Sausage]

I know the solution to this, use a lower voltage pump motor.

 

[Besoeker]

I know the solution to this, use a lower voltage pump motor.

Even more current for the 60HP.

As others have said, the whole thing is just wrong.

 

[trev]

Even more current for the 60HP.

As others have said, the whole thing is just wrong.

It's out in the sticks, who cares if the cable gets hot. It's Malaysia anyway, it's always hot
Hang on, I've not thought that through properly have I

 

[Knobhead]

It may suit the dodgy cable but more parallel cables will be needed.

Somehow I don’t think this OP will be back so this is all academic.

 

[PEG]

I GENUINELY feel for the OP,i have worked in countries where an undersized cable ranks VERY low in the scheme of things...regs,calcs,reason...all play secondary to circumstance,standing and level in the pecking order. IF,the OP is responsible for the cable carry-on,his penalties will range from zero to fatal,depending on who he knows. I have watched site operatives in these areas,drag SWA with a Cat loader,stripping the outer and splaying wires and cores,and when pointed out,if a response is even given,it refers to it being the electrician/agent/architects fault. I have gazed daily on hideous life-endangering work practices,repeated so often it becomes normal practice. I have also seen men die,on site,as a result of such predictable,habitual behavior,the job being stopped only if the deceased belongs to the dominant creed...What it did was make me VERY aware and grateful,for the level of safety we take for granted. HSE gone-mad aside. So,to the OP,you DO have my sympathy,regardless of who the spinning bottle points at,it could be worse,YOU havent got your regs book cover changing colour...:coolgleamA:

 

[Knobhead]

A very nice soliloquy PEG. It still won’t work!

 

[Knobhead]

Dear god!

I’ve just looked at the pictures the OP posted.

I’ve seen some bodge ups in my time, it takes the art of cable jointing to an all time low.

 

[Guest111]

Dear god!

I’ve just looked at the pictures the OP posted.

I’ve seen some bodge ups in my time, it takes the art of cable jointing to an all time low.

Oh come on Tony,maybe they don't have quality street tins over there.lol

 

[Engineer54]

It still wouldn't be big enough, not by a long chalk!

Just re-read what i wrote, ...pretty sure i meant to write additional instead of ''another''!! lol!!

Didn't want to give too much information as i'm not convinced that the OP is a fully qualified electrician, and is still relying on a supervisor that doesn't have much idea of what he's doing either!! lol!!