need a regulated 120

I have a facility that has high line power going into the primary side of a xformer. The secondary side is showing 135Volts which is causing some component issues. I was thinking of tripp voltage regulator/surge suppressor (LS606M) to regulate 120V. Is there anything else that is fairly inexpensive? Din rail mountable voltage regulator?
Thanks

How big is the transformer? (thinking just replace it with a better match)
Does it have multiple taps?

Does the incoming voltage vary?

We used these to alleviate voltage variations and surges with great success protecting antique PLCs and everything else on the tire machines at an old job:

http://www.alliedelec.com/power-protection/constant-voltage-transformers/

They're not ot cheap, though, so only go that route if you have a serious voltage variability problem.

Those are too expensive. Ill have to get more info tommorow but I am thinking the existing xformer is a 4:1.

Constant Voltage Transformers - but you've been told that already. Yes, they're expensive, but are they cheaper than the downtime and replacements??

But WHY are you getting 135? I would honestly be looking at that problem, not putting a bandage on the secondary issue...

I believe the rep for the facility said they are getting over 500 volts on the primary. Said the electric company is allowed to be up to 15% high which could potentially be up to 552Volts. Sounds like they are running high probably around 520.

Sounds like you should have the utility retap the transformer. Most medium voltage utility service transformers (the one that steps down to 480 that feeds your facility) have a tap switch. This is not something you can do yourself, you need a hot-stick and special tools to keep from being electrocuted. A utility company lineman should be able to do it without shutting down your facility.

Look up buck/boost transformers. Use a control transformer, 24 volt out, center tapped. Current draw is based on the secondary side. If your current draw is less than 5 amps, a 150 VA would do fine. Using the 12 volt tap should get you close to 120V. You can double the current by paralleling the secondaries. 10 amps for a 150 VA.
No regulation, just drop.

The buck/boost transformer seems like a good option, but I am not familiar with them. I saw they come in 12, 16, 24,... volts, does that mean it is possible to buck or boost the voltage the equipment sees by 12, 16, 24, and so on voltage. So for my needs taking 130 volts down to say 118 with the 12 volt model?
thanks

Yes. Think of it like this. If you connect 2 transformer windings in series, they will add if in phase, subtract if out of phase.
There are genuine buck/boost transformers, but any transformer will do it.
Connect 120 primary and 12 volt secondary in series. 120 side to neutral, 12 volt side to hot. Take output from neutral and series tap.

Buck -boost transformer may be a viable option. Check this link for selection help:
http://www.solahevidutysales.com/buck_boost_transformers.htm

Bucking or boosting is always an option - but if your supply voltage is High it may not solve the problem.
- Are you close to a terminal station or switching large?
- What is your supply voltage
- What time of day have you measured this.
- Check voltage at other times
- Are there large energy consumers near you?
you may be better with a Variac Xformer.
If your supply voltage is High
you need to check that with your supplier.
the supply should be within 10~15% of normal accepted ammount.(415v in Aus @ 50 Hz)
If you are in an industrial area - the supplier often adjusts the voltage to suit the end of the wiring run - so your supply is higher.
this can be caused by line loading - the supplier can fix this.
- not sure about their liability there - but in AUS if equipment is damaged by over voltage it can be easilly be claimed back to the supplier.
They realise it is their problem - not yours

matlark said:

I have a facility that has high line power going into the primary side of a xformer. The secondary side is showing 135Volts which is causing some component issues. I was thinking of tripp voltage regulator/surge suppressor (LS606M) to regulate 120V. Is there anything else that is fairly inexpensive? Din rail mountable voltage regulator?
Thanks

Click to expand...

It may not fit your budget, but, the CVT (Constant Voltage Transformer) is your only best and only choice, if you have no control over the incoming line, or if your facility is unwilling to correctly tap the voltage of their substation.

Here's one for 35 bucks... http://www.ebay.com/itm/NEW-Sola-Ty...uit_Breakers_Transformers&hash=item5ae468e51d

I say:
1) If the incoming voltage is variable, use a CVT at each position where you have problems.
2) If the incoming voltage is steady, re-tap the secondary:

Thanks for all the info!

Are you maesuring to ground? Are you sure your neutral is not floating?