Installation of 50A Autoformer and EMS

[JCAT]

After considerable online research I purchased the Hughes 50A Autoformer with Installation kit and Progressive Industries 50A EMS with 2nd remote readout.

I have found that some people have chose to install the EMS ahead of the Autoformer and others have installed the Autoformer ahead of the EMS. Each installation having their respective features.

I would like to know which installation is most prevalent for good reason and if it is necessary to wire the devices with the ATS such that the generator also has the benefit of either or both devices.

John

[GaryKD]

Hi JC3625Cape,
Both my devices are wired before the transfer switch.

I've had the voltage regulator (in your case the Auto-former) before the surge protector and behind the surge protector. After loosing two voltage regulators to electrical surges I am now placing the voltage regulator behind the surge protector.

[vsheetz]

I would place the autotransformer after the EMS. Let the EMS provide the overall protection, and then the autotransformer do it's thing. I do similar with a power conditioner just for ham radio equipment in the coach.

[tm2go]

You should heed the the recommended install by the builders of the voltage boosters and the surge protectors. By placing the booster after the surge protector it defeats the surge protector. Hughes Autoformers can fail in the full boost mode, in other words the contacts may fuse together in high boost mode without you knowing it. Should you plug in somewhere that already has high voltage you can have over 130 volts. Surge protector is designed to prevent low or high voltage from entering coach. You may save booster from bigger spikes by placing after surge protector but surge protector is the "insurance" not the booster. Have had my booster "stick" in full boost and surge protector saved coach from big money damage. Is design issue with Hughes.

[Steve Ownby]

Originally Posted by JC3625Cape

After considerable online research I purchased the Hughes 50A Autoformer with Installation kit and Progressive Industries 50A EMS with 2nd remote readout.

I have found that some people have chose to install the EMS ahead of the Autoformer and others have installed the Autoformer ahead of the EMS. Each installation having their respective features.

I would like to know which installation is most prevalent for good reason and if it is necessary to wire the devices with the ATS such that the generator also has the benefit of either or both devices.

John

The only configuration that makes sense in my mind is this:

Power pedestal -- Autoformer -- EMS -- Transfer switch.

[palehorse89]

Originally Posted by tm2go

You should heed the the recommended install by the builders of the voltage boosters and the surge protectors. By placing the booster after the surge protector it defeats the surge protector. Hughes Autoformers can fail in the full boost mode, in other words the contacts may fuse together in high boost mode without you knowing it. Should you plug in somewhere that already has high voltage you can have over 130 volts. Surge protector is designed to prevent low or high voltage from entering coach. You may save booster from bigger spikes by placing after surge protector but surge protector is the "insurance" not the booster. Have had my booster "stick" in full boost and surge protector saved coach from big money damage. Is design issue with Hughes.

If stuck in high boost getting 130 vac it is not going to hurt anything, the voltage would have to get a lot higher than that to do any damage, Actually everything would run better and cooler on that voltage compared to lower voltage. Most autoformers have boost indicating lights and I would think that one would see fairly soon if it was lit up and boosting, and then check things out. I don't want to mail or ship my autoformer anywhere for service as it is heavy and would be costly to get repaired. Surge guard first for me and when it see's 103 vac it shuts down, add together the 10% boost my vac was running at 113 vac, on the high end it shuts down at 132 vac,that voltage is time for my equipment to be shut down and see what the problem is. 120 vac is the normal, 113 vac is low, things run hotter and won''t have a long life span. I will take 120-130 vac anyday.

[tm2go]

May want to look closer at items in question. Surge protector has high voltage cut out at 132 volts. Hughes Autoformer has 10% boost capability. Autoformer has mechanical electric contacts. Contacts can stick causing over boost way past 140 volts. This is not an unknown condition. Call Hughes direct and question the designer of unit to see if what I say is not correct. Have been to Hughes in person with my "stuck in over-boost" unit and did talk to designer about issue. Yes, 120 volts is what you want but not over 132, as that is danger zone. Is why surge protectors shut power off above that. Hughes do have lights, are you going to mount unit so you can watch lights 24/7 ? Are you going to watch any other voltage indicators you may have 24/7 ? That is why the builders of surge protectors say to put voltage conditioners first. Booster repair is cheap compared to everything else. Hughes told me expected life of contacts is approximately 10,000 cycles or several years of normal use under normal conditions.

[palehorse89]

I believe my Hughes has shutdown limits built in also and I don't believe it has contacts , it is done on a circuit board I think. I could be wrong, but when I had the top off I don't remember seeing any pick-up contacts, just a big winding coil and circuit boards.As stated "would see it fairly soon" , you and I know we can't watch something 24/7 as we would fall asleep without knowing it till we woke up. We can do the best we can to avoid problems.

[tm2go]

An additional note: Hughes has said in case of "stuck" contacts to disconnect unit from power, place piece of wood under unit (like a bigger base), lift unit up a foot or two and let it drop, which may break the arced together contacts apart. This may work as temporary fix for unit until you get contacts replaced. Not my words but direct from Hughes. At one time Hughes planned on a unit that was solid state that was supposed to address this type of problem. Don't know if they ever did. You be the judge about trying to fix " stuck" electrical contacts by smacking them. Think about body protection in that type of operation. By the way, Hughes also says to place their unit first.

[palehorse89]

Originally Posted by tm2go

By the way, Hughes also says to place their unit first.

I just got done reading their installation manual and went through their whole web site and saw no mention of pairing the auto former up with surge protection and or placement or arrangement of both? Hughes states that thier autoformers already have both built in, surge and over/under voltage. As always, I might of missed something......

[tm2go]

For what it's worth, I still use my Hughes 50 amp unit in a full-timer motorhome, yes, it does work and at the same time do not endorse or discourage others from Hughes products. Was only trying to put some information out for others to see and consider. Always good idea to speak directly with people who have built the products you buy that you may not be an expert in and to carefully read any manuals or other documentation. I do have additional electrical indicators and audible alarms in coach along with several fire extinguishers inside and in bays.

[tm2go]

During my visit at Hughes to fix my Autoformer the designer/engineer of same explained all the features of his units. Yes, they have high/low voltage limits and some surge protection but unit was not designed as surge protector but as voltage corrector as main function. Did say surge protector after his unit could be beneficial. The TRC company that makes SurgeGuard also told me to place voltage booster first as they recommend for their booster unit. Phone calls still work these days. Anything electrical or mechanical can fail at any time for almost any reason as everyone knows.

[Craig_R]

Originally Posted by Steve Ownby

The only configuration that makes sense in my mind is this:

Power pedestal -- Autoformer -- EMS -- Transfer switch.

I agree with Steve on this. If the Autoformer delivers a voltage in excess of 132 VAC the PI EMS will shut down to protect the coach. The PI EMS also protects against power surges with a total Joule rating of 3,580, 88,000A surge current. Response time of <1 nano second. That's from PI's website.

If the EMS is placed ahead of the Autoformer and a scenario like TM2GO lays out in his above post were to occur then the coach is unprotected. Besides, the PI EMS has a Lifetime Warranty. If something is going to fry, let it be the PI EMS, that's it's job.

["007"]

Thanks for the added info tm2go, a SURGE PROTECTOR is a good option to have with all electronics in coach's these days.