30 amp or 50 amp surge protector

[Kenny kustom]

I have mounted my display " outside" on my last two units.
It makes no difference to me.. it will do, what it does...
if there's a surge, it will disconnect. It requires no input from me.

[BBQGUY]

Adapters/dogbones are known to overheat well before the wires in the cable will or the breaker trips. Get the right size EMS for your unit so you don't have to use the adapters and worry about an electrical component failure.


As to using 50amp vs 30amp service at a park pedestal.
If its the breaker usage issue: most breakers are service rated, i.e. can be used like a switch. Older breakers may not be.
Have also heard people making a breakout box to separate the 2 legs of a 50amp service, checking the voltage on both legs and choosing the highest one to connect to. The latter makes more sense for using the 50amp service.

[270S]

Originally Posted by m35a2

Does surge protection work based on input voltage only?

Because otherwise without modification it doesn't make sense that a unit designed to support 50 amp service ( which can provide up to 100 amps of current if I understand correctly) would trip correctly if plugged in to a 30 amp pole.

The circuit breaker in the camper should still protect you I guess. But it seems counterintuitive.

NO, don't confuse the many features of the PI EMS (Electrical Management System). In addition to the surge (typically due to an electrical short somewhere) protection which is based on AMPS - hence 30A or 50A, not the voltage. The rest of the EMS part monitors/displays/cuts power if out of limit for the following:

• Reverse Polarity Protection
• Open Ground Protection
• Open Neutral Protection
• High Voltage Protection
• Low Voltage Protection
• High Frequency Protection
• Low Frequency Protection
• Provides Amperage Usage Reading

By the way, I have a personal disagreement with the nomenclature of 50A service. Sometimes it is a single 6AWG circuit and other times it is 2 which yields 100amps available, but still called 50amp referring to 6AWG wire size only. But as that is how the industry labels it, we must agree or ____. IMHO should be called 2x50 or 100A combined - Bit of professional disagreement there. As long as we understand the language used.


Funny, in the PI error Codes, it says to contact Camp Manager for All Codes E0-E6 - E0 is normal operating conditions. I guess PI expects ABNORMAL operating Conditions as Standard at campgrounds - LOL.

[emm-dee]

I did a minor wiring mod and mounted my PT30 portable Unit inside the trailer. Just open one of the kitchen drawers to view the display. Works just fine.

[325BH]

Originally Posted by 270S

By the way, I have a personal disagreement with the nomenclature of 50A service. Sometimes it is a single 6AWG circuit and other times it is 2 which yields 100amps available, but still called 50amp referring to 6AWG wire size only. But as that is how the industry labels it, we must agree or ____. IMHO should be called 2x50 or 100A combined - Bit of professional disagreement there. As long as we understand the language used.

"50 amp service" is a 240/120 volt service... which is 50 amps at 240 volts. This means each hot can carry 50 amps. In addition to two hots, there is a neutral present which allows 120 volts.


There is no 50 amp service that has only one leg/hot.

The 200 amp service in your home is at 240 volts. If only 120 volt circuits are used you have 400 amps available. Since you have a mixture of 240 and 120 volt circuits, you have a mixture of "amps". However it really isn't more or less amps, you are simply using one or two hots.

The wire is not being overloaded when we say 50 or 100 amps. The service is "50 amps" but is commonly known to be a 240 volt circuit thus the 50 amp statement. Since our campers only use 120 volts, the available amps is doubled... because all of the amps draws of our camper's electrical devices are all stated in 120 volts because that is what they are.

The "30 amp service " that our campers use is a 120 volt only service... so it is only 30 amps. There is only one leg.

Unlike the 30 amp service which is a camper/RV specific NEMA plug/receptacle (NEMA TT-30), the 50 amp service is not camper/RV specific. It is a regular NEMA plug/receptacle (NEMA 14-50) most commonly found in your kitchen for the electric oven/cooktop combo.

The TT-30 has one hot, a neutral and a ground.
The 14-50 has two hots, a neutral and a ground.

The 50 amp service has 70 more amps than the 30 amp service.

Although most salesmen know no better, the 50 amp service gives you MUCH more than a 2nd air conditioner. Even from the factory you get more circuits... with available spaces in the breaker box. And you can run everything at the same time without risk of tripping the main breaker in your box or on the pedestal.

[Iwannacamp]

Originally Posted by 270S

IMHO, because of my businesss background, I would only use a hard wired unit with a remote display that you can monitor at ALL Times inside your unit. If it is outside, it is very likely you will not see the event you are waiting to see never happen. Get the right one now (30A) and leave it with the unit if you sell or trade it in. Then get the right size (30 or 50) for the next (if ever) unit. This may or may not save/cost $, but you will rest easy knowing you DO HAVE the right one. Not the time to save a few $s.


It would be like having your fuel gauge hanging from the fill door while you are driving. Of course you will go outside in the thunderstorm to make sure everything is OK.

X a couple

[m35a2]

Thank you to everyone for a super informative thread.

This thread piqued my curiosity so I did a little digging.

In regards to surge protection:
Basic surge protection works the same (50A or 30A, whether on a pigtail or one of the PMI power monitors.) All utilize MOVs for surge protection. MOV are triggered by a specific voltage (for home and RV use, that voltage is 330V).
If input voltage exceeds 330V the MOV operates, essentially creating a short circuit and protecting your stuff from getting zapped.

50A and 30A suppressors USE THE SAME MOV. So my earlier concerns about a 50A suppressor not operating correctly hooked to 30A service are 100% baseless. 50A and 30A suppressors provide exactly the same surge protection.

A suppressor's Joules rating has to do with whether the surge suppressor will survive an surge condition. A 50A suppressor has about twice the Joules rating so it can take about double the punishment that a 30A can before it fails.

Where the PMI unit really shines over a plain old surge suppressor is that it can detect overvoltage at a MUCH LOWER VOLTAGE (139V I believe) and possibly remove power before the MOV can (MOV operate at 330V). I say possibly because the MOV will still operate faster if the spike is near instantaneous.

The PMI low voltage disconnect is a big advantage too. Low voltage is bad for things with electric motors like air conditioners.

Summary:
A 50A will work just fine on a 30A camper.
A PMI is worlds better than a plain old surge suppressor.

I returned the surge suppressor I just bought and ordered a PMI.

[325BH]

Originally Posted by m35a2

The PMI low voltage disconnect is a big advantage too. Low voltage is bad for things with electric motors like air conditioners.

Agree with everything you said (not just what I quoted). In addition, I will say low voltage is the condition I most frequently encounter (which causes my PI EMS to cut power)... which prompted me to buy a Hughes Autoformer.

[m35a2]

Originally Posted by 325BH

Agree with everything you said (not just what I quoted). In addition, I will say low voltage is the condition I most frequently encounter (which causes my PI EMS to cut power)... which prompted me to buy a Hughes Autoformer.

Ay caramba man.. Those things are pricey!
I may have to wait until the War Department experiences life with no AC due to low voltage before I attempt to procure funding for one of them.

[bushdad]

I am also going to buy one, what does everyone use to stop people from stealing it ?

[325BH]

Originally Posted by bushdad

I am also going to buy one, what does everyone use to stop people from stealing it ?

I use a bicycle cable lock through it and my stabilizers. Nothing bolt cutters can't get around... but better than nothing.

If I remember correctly, it comes with a cable lock.

I have several of the cable locks. I have the Autoformer, a surge protector for the pedestal... and a plug-in EMS that I bought before I got a hard-wired one. I still carry the plug-in for backup since I already have it.

Soon I will be visiting a campground with known voltage (low) issues. Last year, at that same campground, my EMS kept cutting power because of it. I can't wait to plug in the Autoformer this year.

My friends kept teasing me because my "fancy electronic gizmo" must be broken... because it kept "losing power." (When it in fact was cutting power due to low voltage.) No amount of explaining helped. All they knew was their ac kept running and mine were not.

[Alan F]

I have a 30 Amp EMS and use a cable lock to secure it. It won't keep someone from taking it if they really want it, it it will slow them down. Haven't had a problem yet, and use it every time I hook up. I use a cable lock for it. I ordered directly from Master Lock, but Amazon also has them.

[Jeff_and_Abby]

Been following this thread with interest, thanks to all for thier contributions ....

We are building up our own Noise Filter / Surge Protection device. It is deliberate that we are not addressing voltage range in this aspect of the design. As far as dollar savings go, when we add in the "fuss" factor, probably not saving a darn thing.

The MOV's ( Metal Oxide Varistors ) which are the active component at the heart of most Surge Protection Devices, should be considered as consumable items. If a real protection event occurs, they will try to absorb or "sink" as many joules of energy as they can, hopefully tripping a protective circuit breaker before they are themselves damaged by the surge energy in the case of a longer-duration event.

The PI EMS ( Progressive Industries Energy Management System ) devices that are intended for permanent installation, are well thought in this area, as the card containing the MOV's is replaceable.

While a "consumed" or damaged MOV will usually fail as a shorted device, they may also physically char or even rupture / explode. As they are a little encapsulated device each about the size of two stacked quarters, they won't cause any physical problem in the event of a catastrophic failure, but one should be aware that ( 1 ) the shorted failure mode could cause the surge protection sytem to simply trip circuit breakers until the failed MOV(s) are replaced, and ( 2 ) the destroyed / open failure modes will simply make the device disappear from the circuit, with no protection provided.

While a "shorted" condition can be checked with a multi-meter, a proper evaluation of an MOV requires an actual test with a pulse power source, beyoned the scope of this discussion.

There is a somewhat accepted practice that these MOV devices have an approximate 15-year life expectancy when connected to power and not presented with any surges to dissipate.

Physical and/or "Solid State" Spark Gap devices can also be used to provide a protection mode. These are seen in some higher-end surge suppressors, but the lack of their presence should NOT be perceived as any sort of lower quality.

Opinion:

Acquiring a 50-amp (Two-leg equals 220 Volt) Device for the 30-Amp (Single-leg, 110 Volt) applications is sort of overkill, half of the device will essentially be un-used, and if it is a non-repairable (i.e. sealed / molded "dog-bone" style) unit, there is a risk that one is over-spending on an essentially consumable device. If only ever planning to run 30-Amp then it might be better to go with a 50-to-30 Amp Adapter at the Post and THEN an an appropriate Surge Protector or "EMS." On a permanently installed and warrantied device, weigh the benefit of future-proofing versus the effort and/or cost of de- and re-installation.

Clearly, in this age of modern electronic equipment, some form of Surge Protection is called for.

Considering prior discussions and giving creedence to peoples experiences, various "EMS" soultions and of particular note, the Progressive Industries solutions, make darn good sense.

Advanced Topics:

Noise Filtering - EMI and RFI ( Electro-Magnetic Interference, Radio Frequency Interference ) suppression is typically beyond the intent of most surge suppression devices. "Not entirely true," many quality surge protectors do have some level implemented with Chokes and Capacitors, but not to the extent required to isolate sensitive equipment from severe noise. The short of it, as current capacity increases, heavy-duty filters become bulky and heavy, at least in relative terms. A 30-Amp EMI/RFI filter is a little metal brick about the size of a hockey-puck and twice the weight, for example.

We derive our voltage protection, as needed, from a couple different devices:

On-Grid, a Tripp-Lite LCR-2400 Auto-Transformer, with a voltage capture range from 89 to 147 Volts. Rated for 2400-Watts, it therefore imposes a 20-Amp current limit. This device weighs a modest 20 Lbs. and requires 4 RU's of space, ours lives in a tool-box repurposed as a four-space rack case.

When confronted with Generator power, we use a SOLA CVS ( Constant Voltage Supply ) which is actually a "Resonant Circuit - CVS Transformer." The Voltage Capture Range is between 95 and 130 Volts, but it will track down to 78 volts with reduced output voltage, approximately 104 Volts.
Pitfalls of this device include approximately 35% no-load current draw, and 85% efficiency at full load. Hence, our 2000 VA ( Volt-Amps ) SOLA draws 7 Amps at no load, and at full capacity, will provide net 16.7 Amps output from 20 Amps ( 2400 Watts ) draw. It also weighs in at an unweildy 117 Lbs. But it will absolutely tame the dirtiest generator power into nice clean sine wave voltage.

Obviously, we have no delusion of operating Air Conditioning or Electric Water Heating, using either of these solutions. Our Specific application is High-End Audio Recording and Production, strictly in the Analogue domain.