Understanding Surge High and low voltage

For this post there are two kinds of RV absorption cooling unit controllers.

ONE you manually choose AC/DC/GAS (DC is optional) the other has a sensor that detects 120vac and auto switches from Propane to Electric.. That sensor is "Exposed" to power surges... However .. Well I know for a fact that at least one company does not bother with surge protection cause they'd rather sell over priced boards.. Which is one of the reason I like Dinosaur boards so much. (They are better designed that said, i've not yet had to repalce the fridge board).

smkettner wrote:

Gjac wrote:
Thanks for all the clarifications. I do have 50 amp service and an old Magnatech converter which does not seem like it would be at risk to high or low voltage. So I conclude for all the replies is that the only thing at risk is the refer board which is a $100 replacement vs a $300-400 surge guard. A special thanks to Mex for an explanation that I could actually understand.

No harm in burning up a Magnetek but I think you are right that it will be fairly tolerant.
Fridge boad AFAIK is 12v powered and should be unaffected. It just signals a relay to send 120v power to the heating element.

Smkettner, thanks for the clarification on the refer. I thought that my board was at risk when running on electric.

Gjac wrote:
Thanks for all the clarifications. I do have 50 amp service and an old Magnatech converter which does not seem like it would be at risk to high or low voltage. So I conclude for all the replies is that the only thing at risk is the refer board which is a $100 replacement vs a $300-400 surge guard. A special thanks to Mex for an explanation that I could actually understand.

No harm in burning up a Magnetek but I think you are right that it will be fairly tolerant.
Fridge boad AFAIK is 12v powered and should be unaffected. It just signals a relay to send 120v power to the heating element.

Hi Niner,

None of the currently available surge protection devices are acceptable to me. Low voltage is the killer far more than surge. I'm comfortable above 109 volts. That's 5 volts higher than where existing devices cut out. At 108, I turn off the air conditioner. At 100, I revert to using double conversion with my inverter powering the RV.

I do always check voltage and polarity before I plug in. Even though I full time, I do still mostly boondock. It is not uncommon for me to have no access to the breaker panel for the outlet(s) I'm plugged into, so I monitor both wattage and voltage. If there is any question of tripping the breaker I change to using double conversion.

In a pinch, there is always a hotel to stay in.

I consider what is currently available to be the emperor's new clothes, as far as performance goes.

NinerBikes wrote:


This is a question for MexTex Wanderer. And I would rephrase the question, can you not afford to have them, if living full time in your rig, without stick and brick as a backup place to live?

pianotuna wrote:
Hi,

So where do we buy an Isolation transformer and a Ferro resonant transformer? And can I afford them?

This is a question for MexTex Wanderer. And I would rephrase the question, can you not afford to have them, if living full time in your rig, without stick and brick as a backup place to live?

Shadow Catcher wrote:
But what of your TV and radio and lights and...We have a large teardrop trailer and I decided on the PI hard wired EMS because things like the laptop and camera and cell chargers are all plugged in. Progressive Dynamics converters have some over/under voltage protection but they will not tell you how much (I called and asked). Magnitec's have a reputation that is less than sterling.

If you read my first post the MH is 18 years old and I dry camp 95% of the time and has a tube TV which I rarely watch. I believe the batteries act as a filter so I don't know how lights can be affected. As far as the old Magnatech it is 18 years old also and still works great. I use my 40 amp B&D automatic charger to charge my 8 year old 6 v batteries then float them for a couple of days with the 5 amp Magnatech charger. I don't think the smart charger fully charges the batteries. I find I can go several more days of dry camping if I float with the dumb Magnatech for a few days prior to camping. When it breaks then I will upgrade.

Well the Magnetek converter is already shot, was the day it was built/designed, so you might as well replace it,, Oh by the way it uses a ferroresonate transformer.

If you want to find one of those for a 50 amp rig.. Prepare for two things to happen.. ONE: a very FLAT wallet,, Two, Hernia. they are big and heavy. I **MIGHT** be able to pick one up but frankly do not wish to try. An Autoformer is heavy enough. and contains a lot less iron.

Someone said an isolation transformer will stop spikes.. I am not convinced of that. Since an Isolation transformer is a 1:1 device, theory has it whatever is presented to the primary should appear on the secondary. That includes spikes. That said, they are not perfect and thus may tend to reduce a spike some.. Still they will not stop a surge or a brownout.

But what of your TV and radio and lights and...We have a large teardrop trailer and I decided on the PI hard wired EMS because things like the laptop and camera and cell chargers are all plugged in. Progressive Dynamics converters have some over/under voltage protection but they will not tell you how much (I called and asked). Magnitec's have a reputation that is less than sterling.

Thanks for all the clarifications. I do have 50 amp service and an old Magnatech converter which does not seem like it would be at risk to high or low voltage. So I conclude for all the replies is that the only thing at risk is the refer board which is a $100 replacement vs a $300-400 surge guard. A special thanks to Mex for an explanation that I could actually understand.

Hi,

So where do we buy an Isolation transformer and a Ferro resonant transformer? And can I afford them?