Surge protection plus a hughes autoformer

[palehorse89]

I have been doing a lot of reading on the installition of a surge guard and a autoformer and which one goes where in the installition? I bought a "surge guard 34560" and a hughes "rv220-50 autoformer" to put in my electric bay. I have read so many posts and every other post tell to do it just the other way that the one before that one said to do it,so my question is: What is the best way to wire both of these up?
Surge guard shuts off if voltage is below 102 volts and above 132 volts
hughes autoformer turns on at 116 volts and turns back off at 118 volts
i just want to do this right the first time and only once, so any input would be great!!! Thank you for the help

[EngineerMike]

If you have the SG before the AF, and volts go below 102, you are out of electricity-in. How low will the AF go before it shuts off? Most electronics are good to 108, some lower, and IIRC the AF goes to +10%. If the AF has no low-volt shutoff, then 108 = 10.8 + 97.2 volts. If the park is at 98 volts, I'm not sure I'd wanna hook up there at all, so the SG in front is probably just fine. If you put the SG behind, you only have high=volt shutoff, practically speaking. So SG in front seems reasonable.

[palehorse89]

From what i have read the autoformer does not have a low voltage shutdown. It just wants to try and boost the voltage by 10%. This is why i also bought the surge protector so the shutdown will take place at 102 volts.my thought was to put the autoformer after the surge protector but i will be shut down at 102 volts on the primary and with the 10% i would loose power at 112.2 volts , but i could still be running in a safe range of 112 volts?

[GaryKD]

Hi palehorse89,
CG post power to voltage regulator to surge protector to coach. I am not an EE. If you call the companies, they should tell you the voltage regulator goes first. This is how I have mine connected. The instructions included with my voltage regulator unit and the tech help desk all say the same.

I use the term voltage regulator because there are different brands one can buy, but they all do the same thing. All voltage regulators do not shut down. Many just stop regulating the voltage below/above what ever the spec calls for. The surge protector is what one should depend on to shut the power down.

[Todd Coffelt]

GaryKD puts everything in the right context.
No matter which manufacture of voltage controller we are speaking of, the range of boost goes from 10% to 16% of incoming voltage. After you research what those percentages mean to the RVer, it is only two volts.
So if the surge protector is after the voltage controller, the power to the RV will be shut down at 104v. This means that the park voltage would be at 93 to 95 volts if this event was to happen.
Thanks

[palehorse89]

Thank you for your input. I have read where the autoformer is first like you say and took a jolt of some sort and had to be sent in. After that the fellow reinstalled it after the surge protector to protect it and had no problems? When the park voltage gets down into the 90's volts area even with a autoformer or voltage controller you are within 2 volts of being shut down by the surge protector. I have read if the autoformer is first and takes a hit it has to be sent in and they are heavy to ship?i am not to sure if i want my ac's running on 104 volts? Sounds low? I am just passing on what i have read and want to know your thoughts on what i have said. Thank you

[wa8yxm]

Here is the sequence
Shore power outlet
Surge Guard
Auto-Former
Auto-Transfer Switch (Optional, only needed if you have a generator)
Power distribution panel

Cords can be between any two

I recommend using the Hughes Install Kit or for less money. make your own. This kit consists of nothing more than a plug, short cord, and socket that go inside your rig near the ATS.. The outlet goes on the ATS-end of the inlet cable (power cord in a trailer) and you plug, normally, the Autoformer into it. in your case plug the surge guard into it.. Then plug the auto former into the surge guard

NOTE: if your surge guard cuts you off in the event of low voltage you will have to re-set the low-voltage cut off to like 90 volts or .. Well I'm not sure how much boost the Hughes gives (You want the cut off to happen about the time the output from the Hughes hits 106)

[palehorse89]

Wa8yxm, the way you said is just what i had in mind . I wired it up last night, powered it up after 2min. 15 sec. The surge protector kicked in andat the same time the autoformer started up.i ran different things in the coach and the autoformer worked as they said it would. I have a 12/3 sow cord just to plug it in to charge the batterys in the winter but i had 121.5 v with no load.started the front ac and the ac fan on low dropped it to 120.4 v. The ac kicked in and the autoformer started up and the voltage 115.5 then i checked the voltage at the output of the autoformer at the transfer switch and it was 126.5. I did not have a amp probe to watch what the amps did, that is going to be my next test just to see what happens there so i know what to say about it if asked. Thank you all for your help