Way to Save Energy Bill By Power Down STand-by Transformers

[Knobhead]

We did have OLTC’s on the intake transformers. The first thing to be done would be to switch them from “independent auto” to “leader and follower auto” to balance the voltage. I’ll have to do a drawing of the setup later today.

 

[shanky887614]

The plants I’ve worked on that had standby generators the switching was all manual. I can understand it for a hospital but the expense couldn’t be warranted for us.

in the hospitals they can have big ups units to keep things running till it goes online.

in one of the hospitals ive had a look at.


they have multiple supplies from the grid with castel keys to swap essential/non essential if need be with backup ups and generators to keep things going.


i had a look at some nice drawings showing where all the suplies for the hospital went from and to.

i learned a lot that day by chatting to the estates after one buggered up the fuse carrier in a full distboard lol

 

[Guest55]

Some interesting insights there from T & E54 in the difficulty in efficiently managing large scale site distrubution.

mostly above my station but i doff my cap anyways.

 

[Engineer54]

Thanks Tony. In our case is a bit different, there is electrical and mechanical interlock to prevent paralleling the transformers as well as paralleling utility power with stand-by generator.

Each time test run of generator with load, we need to power down the entire distribution network within our plant (total blackout), as such there is no issue of switching.

.

Please tell me you are joking, ... you need to shut down the companies entire MV /LV distribution system to test run the generator??? I've never heard anything so bloody ridiculous in all my working life!! Who the hell designed such a head banging system as that??


And you're worried about saving a few $'s by shutting down a couple of Transformers. Your company needs to be spending money to sort out it's site wise MV/LV distribution system, before thinking about saving a few dollars and screwing the overall system up even further by the sound of it....

 

[gnuuser]

Please tell me you are joking, ... you need to shut down the companies entire MV /LV distribution system to test run the generator??? I've never heard anything so bloody ridiculous in all my working life!! Who the hell designed such a head banging system as that??


And you're worried about saving a few $'s by shutting down a couple of Transformers. Your company needs to be spending money to sort out it's site wise MV/LV distribution system, before thinking about saving a few dollars and screwing the overall system up even further by the sound of it....

besides the best way to save money in an industry is to keep the machinery in proper working order. this means a rigidly followed planned maintenance system. for example current draw monitoring & proper lubrication of equipment.
well lubed machinery creates less friction on motors, less workload equals less current draw
less current draw equals a lower power cost.
also on the note of preventative maint. dirty cooling fins on motors!
dust build-up on cooling fins can cause excessive heat retention in a motor, this can cause early failure of the lubricant and early failure of bearings. drastically reduced active life of the motor.
simply setting up a schedule of frequent cleaning (blowing dust out with compressed air) can keep a motor running for many many years.

 

[Knobhead]

Please tell me you are joking, ... you need to shut down the companies entire MV /LV distribution system to test run the generator??? I've never heard anything so bloody ridiculous in all my working life!! Who the hell designed such a head banging system as that??

We’re back to that again. There’s a big difference between a hospital and an industrial plant where the loss of power is no great shakes.

If the plant can cope with an outage why waste money on unnecessary expensive equipment? Admittedly it’s inconvenient but it’s not the end of the world.

How many places are there with no standby power at all? They manage.

 

[Engineer54]

We’re back to that again. There’s a big difference between a hospital and an industrial plant where the loss of power is no great shakes.

If the plant can cope with an outage why waste money on unnecessary expensive equipment? Admittedly it’s inconvenient but it’s not the end of the world.

How many places are there with no standby power at all? They manage.

Are you actually telling me this is common practice, Come on Tony pull the other leg it's got bells on!!! I haven't only worked on Hospital Stand By systems, be they MV or LV.

Black out an entire company's site to load test a generator, ....the design is a complete NONSENSE, this has nothing to do with the system being automated. We both know there is absolutely no reason to shut down a complete site to bring a generator online, especially just to load test the bloody thing!!

 

[Knobhead]

It is interesting to note that you have a knock on effect when paralleling 11KV transformers, isn't there an instrument to check and enure in phase as well as minor voltage different before paralleling the transformers? I guess the 33KV/11KV transformer is equipped with OLTC that has an AVR to regular the secondary voltage.

We did have OLTC’s on the intake transformers. The first thing to be done would be to switch them from “independent auto” to “leader and follower auto” to balance the voltage. I’ll have to do a drawing of the setup later today.

Red is the supply company’s equipment
Blue is our equipment

You can see what the results would be if a bus coupler anywhere in our system was closed without either the 33 or 132KV bus closed.
It only took a phone call as the supply company’s switchgear was remotely operated but they charged us for every time they pressed a button.

 

[Knobhead]

Are you actually telling me this is common practice, Come on Tony pull the other leg it's got bells on!!! I haven't only worked on Hospital Stand By systems, be they MV or LV.

Black out an entire company's site to load test a generator, ....the design is a complete NONSENSE, this has nothing to do with the system being automated. We both know there is absolutely no reason to shut down a complete site to bring a generator online, especially just to load test the bloody thing!!

We don’t know how the generator is tied in to the OP’s system.

I’ve wrongly referred to standby, it should be emergency.

I didn’t say its common practice in the UK, that’s your inference.
If it won’t cause problems and the company can put up with the inconvenience who are we to criticise?
From the contacts I have in Malaysia a power outage isn’t unusual. It isn’t unusual for a plant to have a backup system. What is unusual is for them to actually test it.
Many are running purely on generators with no backup.

Our emergency generators were remote from the intake. In the event of a major failure power is transmitted via the MV network to wherever needed, everything else would be isolated. We could generate only a tiny portion of the intake total to keep essential site services going.
The only time I’ve known an emergency system used in anger. The RAF had to fly food in as the works was totally snowed in and all the power lines were down.

Yes I have worked on fully automated systems with UPS backup. But in general industry they are few and far between.

Our two data centres each had their own standby system. The joys of multinationals, they’ll spend money like water for the management side of things. You try getting money out of them for essentials.

 

[Engineer54]

We don’t know how the generator is tied in to the OP’s system.

I’ve wrongly referred to standby, it should be emergency.

I didn’t say its common practice in the UK, that’s your inference.
If it won’t cause problems and the company can put up with the inconvenience who are we to criticise?
From the contacts I have in Malaysia a power outage isn’t unusual. It isn’t unusual for a plant to have a backup system. What is unusual is for them to actually test it.
Many are running purely on generators with no backup.

Our emergency generators were remote from the intake. In the event of a major failure power is transmitted via the MV network to wherever needed, everything else would be isolated. We could generate only a tiny portion of the intake total to keep essential site services going.
The only time I’ve known an emergency system used in anger. The RAF had to fly food in as the works was totally snowed in and all the power lines were down.

Yes I have worked on fully automated systems with UPS backup. But in general industry they are few and far between.

Our two data centres each had their own standby system. The joys of multinationals, they’ll spend money like water for the management side of things. You try getting money out of them for essentials.

I've asked the OP how the generator(s) are hooked up in his system and had nothing back. I have no idea at the moment if the generator(s) in question are MV or LV, i'm assuming at the moment they are MV...

The only area one would then be interested in, is then the MV bus, and if as shown in the single line drawing there are bus couplers, a generator or generators could quite easily be incorporated on that bus. We are basically talking blind here, as the OP states they have 4 subs on the site one 11kv /6kv and 3 X 11kv 0.433kv. We don't know if the 11kv is distributed on an open ring, distributed from a main or central Sub via radials, or individually supplied by the local electricity company. We also don't know if the standby generator(s) covers the whole distribution system or section(s). Either way it's not physically a problem to incorporate stand-by facilities WITHOUT having to shut down the entire sites distribution system....


Perhaps it is just me, but i can't see how any company Factory(s) that requires the amount of energy as indicated by the OP can substantiate a total blackout to test run a generator or generators. It's a totally alien philosophy, that i've never come across or even heard of during my working career.


Oh and BTW i have worked in Penang, well just across from Penang at the Butterworth military air base back in the 80's, when the Aussie's air force were based there. Refurb of aircraft hangers and associated workshops, that involved a pretty extensive MV ring too with stand-by facilities. But the base wasn't shut down to bring the those stand-by facilities on line!! lol!!

 

[Besoeker]

We’re back to that again. There’s a big difference between a hospital and an industrial plant where the loss of power is no great shakes.

If the plant can cope with an outage why waste money on unnecessary expensive equipment? Admittedly it’s inconvenient but it’s not the end of the world.

How many places are there with no standby power at all? They manage.

Of course there's a difference. One could potentially cost lives.
The other - well, just jobs.

It is a big deal in a production plant.
I remember sitting having a cup of tea in the electricians' shop in a paper mill. It was during the commissioning phase of some new drives. The usual hurry up and wait that such projects inevitably entail.

Had done a few crosswords, took a spin on Fred's Cotton motorbike. He wasn't far wrong when he said it handled like a wheelbarrow. Slight disagreement on that one - I've had wheelbarrows that handled better.
Bored electrical engineer. So, in the absence of anything more interesting to do, started to read the notices on the notice board. Yes, it can be that bad and sad.. Middle of the night, just waiting and waiting and waiting for a mechanical problem to be resolved.

Picture painted.
Back to the noticeboard. Something that caught my attention - and has stuck with me. "Down time on this machine costs £77 a minute."
The message was clear.
It goes wrong, you move. You get your arse in gear. Instantly.

That was in 1977. In today's money it would equate to quarter of a million a day.

And that's just down time. A power outage? Who knows......

 

[Engineer54]

Back to the noticeboard. Something that caught my attention - and has stuck with me. "Down time on this machine costs £77 a minute."
The message was clear.
It goes wrong, you move. You get your arse in gear. Instantly.

Yep, i can remember during my training days when depending on which line was down, it cost the company between 1500 to 3000 pounds every couple of minutes. After 5 minutes of a line being down it warranted the plant managers presence as well as a host of other dignitaries. Let's just say it didn't happen too often!! lol!!

 

[Besoeker]

Yep, i can remember during my training days when depending on which line was down, it cost the company between 1500 to 3000 pounds every couple of minutes. After 5 minutes of a line being down it warranted the plant managers presence as well as a host of other dignitaries. Let's just say it didn't happen too often!! lol!!

You will probably have gathered by now that we do do variable speed drives, mostly for production machinery. If you hadn't, please pay better attention from now on!!!!!

Because of the cost of down time, we have 24/7 call-out contracts with a number of major customers with guaranteed mobilisation times. That is, someone on their way within a specified time from when the call is made - enough time to get up, have a shower, and not a lot else.

Of course with a continuous process it runs 168 hours a week, Saturdays, Sundays, day and night, high days and holidays. So there is a better than 75% chance that if anything goes wrong it will be anti-social timing.

And, if any of my guys have a problem, they are not averse to calling me at two in the morning. Windmill theatre here it seems like at times.
"We Never Closed"

 

[chlee-penang]

 

[chlee-penang]

Dear Gentlemen,

Thanks for all your kindness in sharing your opinion. I must apologize for not giving the entire picture, I several attempts to paste the MV/LV Distribution Network but failed upload the message, I will try again and hope with the image can clear your doubt.

As we are not allowed to parallel with the national grid, and there is electrical and mechanical interlock to prevent so doing, therefore each time test run the generator with load, at least a section of bus bar has to be completely powered down; it is a common practice here, no generator is allowed to parallel with the grid, with some exception such as handful of Independent Power Producers. Recently there are Solar Power sold to Utility company being export to the grid.

I did commissioned a black start generator for the Utility company, the diesel generator is designed to parallel with station MV Distribution System which is connected to the grid, the site acceptance test with load is done by parallel with station MV Distribution System without power interruption.

 

[chlee-penang]

I paste the entire MV/LV Distribution Network image in Editing mode, it pops up following message:

"The text that you have entered is too long (29790 characters). Please shorten it to 20000 characters long."

I guess there is restriction to the size of image that one can post.

 

[chlee-penang]

Hi Tony,

Thanks for sharing. I see your point now. I learn a lot from you.

 

[chlee-penang]

I made several attempts but fail to paste the MV Dist. Network.

You are right, the generators power is fed through 11KV Bus Bar, but with electrical and mechanical interlock. the interlock is so set up to prevent 1) parallel between two transformers, 2) Parallel between Utility power with generator power.

I am glad to know that you been based in Penang! I wish you did enjoy your stay then.

I am curious how did you bring the stand-by facility without brief power interruption, unless the base is granted the right to parallel the generator with the national grid (I guess is then call NEB or LLN) first before opening Utility Incoming breaker.

 

[Knobhead]

Yep, i can remember during my training days when depending on which line was down, it cost the company between 1500 to 3000 pounds every couple of minutes. After 5 minutes of a line being down it warranted the plant managers presence as well as a host of other dignitaries. Let's just say it didn't happen too often!! lol!!

The joys of being a bad grumpy git. Enter manager “who’s on the job” "TNT" exit manager.

My shift fitter was also called Tony. We didn’t get the nickname TNT for nothing!

 

[Knobhead]

I made several attempts but fail to paste the MV Dist. Network.

I'll PM my e-mail address, send the drawing to me and I'll post it for you. You don't seem to be having a lot of luck.