UPS Wiring

[pentium]

Okay, so when I got my HP 9000 I also got a massive UPS system consisting of two bajillion pound 2U battery packs and another ten bajillion pound inverter/voltage regulator. The whole thing inputs and outputs 200-240V.
Anyways, While I was assured it worked the last time it was powered on I'm having trouble wiring it up. The best place in my house to get a 220V connection is my dryer. The dryer outlets here have +120v, -120v, common (neutral), and ground. The UPS on the other hand is not wired in a four wire setup. All you are given is a ground terminal and two other terminals marked "N/H2" and "L1/H1" From what it looks like you can't use the ground terminal as the common so that means you somehow have to get a 220v connection from +120 and -120 which sounds okay until you relize that with no place to put the common wire you can't complete the circuit.
Can someone explain what's going on here?

[Krankshaft]

Re: UPS Wiring

I had to run a new branch line for 220V baseboard heaters so I can clear this up.

The ground terminal is the return.

A 220 line is usually wired as follows with standard 3 conductor Romex (has a black, white, and uninsulated or green insulated ground) both the black and white lines are wired onto each of the ganged (they flip at the same time) 2 20 amp breakers at the service panel (in other words the black and white lines are LIVE) and the copper ground is the return.

If you look in a service panel both the ground and neutral are screwed into the same buss bar and therefore are at the same potential. This doesn't apply to branch service panels (a smaller panel on another floor for example only the main panel). Electric codes prohibit tying the ground and neutral on branch panels (they call it bonding) this can only be done at the main panel.

If you were to stick your DMM set to AC into that 220 outlet you would read 220 volts between the two prongs if you were to stick one probe in the ground you would read 120V on each prong.

A 220 line is nothing more than 2 live conductors (on a ganged circuit breaker so they shut off at the same time) feeding into a common return. A 120V line is one live conductor feeding into the same return.

Why doesn't this UPS have a standard 220V plug was it hardwired?

[Krankshaft]

Re: UPS Wiring

Sorry used the wrong terminology the ground is not the return in the conventional 120V sense.

Each breaker pole is 180 degrees out of phase so there isn't a neutral the ground is just safety ground to protect the chassis of the device plugged in.

When one phase is positive the other is negative. So the circuit is always completed.

This is why you can measure across the two live top prongs.

If you're outlet has 4 prongs then that's because the dryers heating element uses the 2 live lines (the 220V power) and the control circuitry like the timers and lights use 120 volts.

In these newer outlets there are the two live lines and a dedicated neutral and a ground. Remember between one live line and a neutral or ground there is 120 volts.

[Krankshaft]

Re: UPS Wiring

You could use the ground as the neutral (since they are bonded at the main panel anyways) but as I said before new codes require a 4 conductor cable to be used so you have a dedicated ground for the 120V devices in the appliance.

For existing installations in certain areas if you have 3 conductor cable feeding your box and you get a new 4 prong appliance you can pigtail the neutral and the ground together to install a new 4 prong outlet with 3 conductor wire.

However some localities prohibit this and require you run new 4 conductor cable.

Ok that was a mouthful I'm done now.

So to answer your UPS question wire the two live lines HOT 1 and HOT 2 to each live prong and the ground lead to the ground at the outlet.

It has no neutral because it has no use for 120 volts. It's purely a 220 volt beast.

Be careful and shut down the power to the outlet if you don't have the proper plug and will be hardwiring for testing. Be extremely wary around 220 it packs twice the punch. Be safe.

As always undertake electrical projects with care and at your own risk.

[pentium]

Re: UPS Wiring

Well that didn't work at all. I wired it up like you said, flipped the breaker and flipped the switch and it's silent. No lights. No fans. Nothing at all. Either it's not getting power, it is not getting enough power or something pooched itself while in storage.

To make my life even more awesome, of all the greatest times for the leads on my DMM to die, it has to be right now. I can't confirm voltages or connections until I get that fixed.

Edit: You could of saved trying to explain to me how you get 220V and how a dryer outlet is wired. I already know that and now you have madly confused me.

[Krankshaft]

Re: UPS Wiring

Most UPSs won't power up if the batteries are toast.

Measure the voltages on the batts sealed lead acid batts only have a shelf life of 3 to 4 years MAX. They die in that time even if they aren't used.

Out of the 8 UPSs I received only 2 of them had batteries that would power up the UPS and provide backup power. Even then they were OLD and needed to be replaced.

[pentium]

Re: UPS Wiring

You are thinking of a whimpy little UPS. This is certainly not your average UPS so I'm quite sure that you can power it up with dead batteries.

[Krankshaft]

Re: UPS Wiring

You could of saved trying to explain to me how you get 220V and how a dryer outlet is wired. I already know that and now you have madly confused me.

What's so confusing? If you knew how to get 220 then why did you ask?

No need to get snippy with those trying to help.

Snap some pics of the insides. If it is an electronic problem so others can chime in.

If the batts register at least 12 volts they can be ruled out.

[pentium]

Re: UPS Wiring

I'll try to take some photos after some sleep. Working nights really takes a lot out of you.
Anyways, I knew how to get 240v, I just don't see the logic in using the ground lead as the common as in most cases the ground is attached to things like the casing.

[PlainBill]

Re: UPS Wiring

I'll try to take some photos after some sleep. Working nights really takes a lot out of you.
Anyways, I knew how to get 240v, I just don't see the logic in using the ground lead as the common as in most cases the ground is attached to things like the casing.

I've done some electrical wiring, and those designations are confusing. What brand and model number is this?

I'm sure you already know this, but for the newbies... For what it's worth, the power company's transformer has a center tapped secondary. The center tap is neutral, and is the white wire to all 120 volt outlets. Each end of the secondary is 120 VAC relative to neutral, and can be either black or red to all 120 VAC outlets. The two ends of the winding combine to make 240 VAC. They are usually run as red and black to any 240 VAC appliance.

The usual installation has a ground rod driven into the ground. This goes to the metal of the breaker box AND to the neutral bus in the breaker box. It is either a green wire (Green / yellow in Europe I understand), or a bare wire in Romex.

An electric dryer is a special case of 240VAC appliance. At one time they had a 120 VAC motor, and the two 240 volt wires and the neutral wire were run to them. This led to the chance that a combination of failures could put the metal of the dryer at 120 VAC relative to ground - NOT nice. For years dryers in mobile homes were wired with a 4 prong cord so the metal of the dryer was tied to ground; this may have been expanded to all installations.

Back to the UPS you are working with. I would have expected to see the terminal block to have three terminals, marked L1, L2, (or H1, H2) and Gnd. The only thing I can think of is it was designed to also be used in an area where the normal 'outlet' voltage is 240 VAC. In that case the labels L1 and N make sense.

What I would suggest is to see if you can find some sort of an installation guide for this thing. Hopefully they will make the proper connections clear. Failing that, I would use a double pole (240 VAC) breaker and run red, black(from the breaker), and green (from the neutral / ground bus) wires to the UPS. The black would go to the 'L1/H1' terminal, the red to the 'N/H2' terminal, while the green would go to the ground or frame of the UPS.

PlainBill

[Krankshaft]

Re: UPS Wiring

The ground lead isn't the common it's just a safety ground incase an uninsulated wire for example touched the case. It's purpose hasn't changed from 120 volt circuits.

A complete circuit is just the two live lines from the 220 breaker.

The return alternates between one live line and the other since they are 180 degrees out of phase when one sine swings negative the other swings positive and vice versa.

Check this image.

http://startproducingmusic.com/wp-co...ncellation.jpg

One wire or phase is the red and the other is the blue. If you scoped both phases of 240 from each phase to ground with a dual channel scope and combined them this is what you would see.

When Wave 1 is at positive potential Wave 2 is at negative potential so Wave 2 acts as the return. Next Wave 2 swings positive Wave 1 now swings negative and Wave 1 becomes the return. This is why a neutral or return isn't needed.

Plainbill made a point about it maybe being made for single wire 240V.

I think this UPS may be dual capable though since it said. H1/L H2/N so two hot leads or one hot lead and a neutral (which would be the set up in Europe with one line at 240V).

[Per Hansson]

Re: UPS Wiring

It sounds to me like a UPS made for 230VAC networks
Like pretty much all of the world except the US uses, like the matric system :P (sorry couldn't resist :P)

Quoting yourself; The whole thing inputs and outputs 200-240V.
It would need to have 2 phase inputs (Phase 1 and Phase 2, plus a Neutral and or ground) to be able to complete a 230VAC circuit in your country

But here in Sweden it would be enough with just Phase 1 plus Neutral and or Ground

I have a UPS like that (still with dead batteries) and I can confirm it very much wont power up with it's dead batteries!

http://www.dansdata.com/danletters176.htm

[Krankshaft]

Re: UPS Wiring

Hey Canada has 120 volts too !

Screw your 240 volts and your "Metric System" .

I've noticed lately when measuring with my micrometer I'm slowly going metric fractional measurements are just too hard to remember.

[kc8adu]

Re: UPS Wiring

the hp ups that was in a 9000 i had years ago had 4 oddesy 12v 26ah agm batts in it.the battery fuse was missing.it will not power up or even pass through if they are dead or the fuse is open.the p.o spent $800 for 2 sets of these batteries then gave up.they were fine being brand new.and it worked with a new fuse.mine had a 220v 20a plug on it.

[Krankshaft]

Re: UPS Wiring

It seems like most UPSs use this no power up to indicate the batteries are dead.

It would be nice if they would flash a replace battery LED or something though.

I guess they don't want it to even pass through power if it can't provide backup power because if it did the operator may think that the UPS is ok and they were protected in case of an outage.

If you had a large beast like that in an office environment there probably would be a company maintaining it who would know what was wrong anyways.

If you do decide to use that make sure you flip your PSU switch to 240 unless you like fried PSU. If your PSUs have APFC they are autoranging and have no volt selector switch.

[smason]

Re: UPS Wiring

Hey Canada has 120 volts too !

Screw your 240 volts and your "Metric System"

Quick, name another country besides the USA that *doesn't* use the Metric system.

[pentium]

Re: UPS Wiring

Okay, for starters, HP called it the Power Trust A2998A.


Next up, here's the back of the main inverter unit.

Power runs in from the wall from the cable ion the far left. The two plugs in the middle come from the two battery packs. the main circuit breaker is on the right.
The bypass switch is set to "normal", the UPS/battery switch is set to "enable" and the EPO terminals are shorted to allow the unit to operate.

Power used to come from a four prong twist-lock plug but it has been rewired to work with a dryer outlet. It's currently wired like so:


The lines run into the UPS and into these three terminals. These have not been touched by me so whichever way it's wired right now is the way it worked at the university.

The BUSS fuses seen in the picture supposedly feed to the output socket so if they have blown they should not prevent it from powering up.

I can't open the unit. There are dozens of screws.
The batteries themselves worked the last time the system was operating which was at the latest, summer 09. Since then it sat in a hallway for a few months before it was moved to my storage room and spent the winter in a cool (10c at the coldest) environment. If the batteries discharged at that time then they ahve gone low enough to start being cranky and not allow the UPS to work. The abttery packs themselves are about half a dozen cells on trays that slide into an enclosure. Other than that, the only other idea is that it's somehow wired incorrectly.

Quick, name another country besides the USA that *doesn't* use the Metric system.

I heard hell uses imperial.

[stj]

Re: UPS Wiring

that 4pin plug looks terrible, you need to rub those pin's down or they may arc or cause heating & damage the socket - i'v seen it happen.

[PlainBill]

Re: UPS Wiring

Okay, for starters, HP called it the Power Trust A2998A.


Next up, here's the back of the main inverter unit.

Power runs in from the wall from the cable ion the far left. The two plugs in the middle come from the two battery packs. the main circuit breaker is on the right.
The bypass switch is set to "normal", the UPS/battery switch is set to "enable" and the EPO terminals are shorted to allow the unit to operate.

Power used to come from a four prong twist-lock plug but it has been rewired to work with a dryer outlet. It's currently wired like so:


The lines run into the UPS and into these three terminals. These have not been touched by me so whichever way it's wired right now is the way it worked at the university.

The BUSS fuses seen in the picture supposedly feed to the output socket so if they have blown they should not prevent it from powering up.

I can't open the unit. There are dozens of screws.
The batteries themselves worked the last time the system was operating which was at the latest, summer 09. Since then it sat in a hallway for a few months before it was moved to my storage room and spent the winter in a cool (10c at the coldest) environment. If the batteries discharged at that time then they ahve gone low enough to start being cranky and not allow the UPS to work. The abttery packs themselves are about half a dozen cells on trays that slide into an enclosure. Other than that, the only other idea is that it's somehow wired incorrectly.

I heard hell uses imperial.

Yes, this is about what I expected. This is labeled to use either a center ground 120/240 VAC hookup (common in offices) or a 240VAC line with one end grounded.

There is one problem that would get an electrical inspector all over you. A white wire should never be hooked to a green wire. The bare copper wire coming from the dryer cable should be hooked to the green wire. Now, assuming the house wiring was done properly, that should not make any difference electrically.

If you search for 'A2998A manual' you will find some information. Apparently this is a rebranded Sola unit. And on this page you have someone with the manual.

I'd take a systematic approach to solving this. First of all, other than the detail I mentioned above, you are wired correctly. The first step would be to measure the voltage across the input terminals. If it reads 240VAC, and the unit won't power up, check the battery packs. Count the number of cells, multiply by 2.1 and you have what should be the DC voltage. In my experience, UPS batteries, particularly the sealed 'gel-cell' type have a limited life. 2-3 years is the best I've seen, and if they are allowed to discharge completely they will die a premature death.

PlainBill

[pentium]

Re: UPS Wiring

Well I'm going to have a heck of a time finding tha manual at the Sola website.
Okay, so assuming the abtteries are dead, is there any way I can jumpstart the unit? I know trying to recharge the batteries now might be useless but a wise man once told me that if you beat a dead horse long enough it will eventually make movements that resemble life.

Also the white going to green is the fault of whoever wired up the UPS in the first place. There are no other wires for the neutral to run along.