Surge protector - to good to be true??

pine tree · 12-25-2009, 06:03 AM

I just bought a Progresssive Industries Mod. SSP-50 [50 amp 240 volt] surge protector on e-bay. It looks like a good device to safeguard our 50 amp motor home. There are lights to indicate corrent wiring and polarity of the camp site electrical source and surge protection built in. The cost was only $100.00, which seems a good deal compared to other protectors that do basicly the same thing and cost much more. Best of all the device was MADE IN THE USA>
When reading the instructions, I think, I may have discovered the reason for the low cost. At the end of the fine print the instructions say - IF THE GREEN LIGHT IS NOT LIT, THE SURGE PROTECTOR IS COMPROMISED AND NEEDS TO BE REPLACED. Ouch, this sure sounds like send in another $100.00.
We are about to start out on our annual Florida winter trip in our new [used] Journey. This rig has more electrical devices and wizz bangs than the law allows, thus my desire to have some protection.
In about 10 years of RVing [Trailers and smaller class C rigs]I have not had any camp site or other electrical problems. I know however, there's a first time for everything and problem sites are out there.

Anyone have experience with the PROGRESSIVE IND. SSP-50 SURGE PROTCTOR?

Should I send it back and pop for the more expensive device or am I good to go. As I see it, the Progresive SSP-50 device is kind of like buying an insurance policy with a big deductable. Protects me from the big hit [cost] on a very unlikely event [loss] at a relatively low cost.
Some help and ideas please!!!

Pine Tree

Rick Long · 12-25-2009, 06:20 AM

ANY surge suppressor, no matter how much you paid for it, that takes a big hit will need to be replaced!!

Oemtech · 12-25-2009, 07:50 AM

Tweety's sells them for $100 all day every day. This is a SURGE PROTECTOR (900 joules) and not a EMS system, all though it does test for correct wiring.

Basically if the Green light is out then one or more of the MOVs (metal oxide varistors) are gone.

wa8yxm · 12-25-2009, 11:28 AM

The primary component in a Spike protector (More on the difference later) is called an MOV, and they do have a life time, Don't matter who builds them how much they cost,, They wear out.

Now... a Spike is a short term increase in voltage.. This is what the so-called Surge protectors protect agains

A Surge, is a longer "Wave" of high voltage, and will blow most surge protectors like a firecracker.. The PD units, however, and many other RV units, monitor voltage and use a different method of protection if a true surge comes along)

MrTransistor · 12-25-2009, 04:03 PM

As wa8yxm and the others stated, all Surge Protectors use MOV (Metal Oxide Varistor, Google ‘varistor’ for more) devices that will short when the Voltage is higher than their rated break-over Voltage. A good surge protector will have several MOVs in it, connected between L1 and ground, L1 and Neutral, L2 and ground, L2 and Neutral, and L1 to L2. I would imagine that the most common reason for a protector to fail is plugging it into a 50 Amp. pedestal with an open neutral. If there is a very low resistance appliance turned on, in the coach like the hot water heater, then the Voltage between the other Line and Neutral will be close to 240 VAC, which can be enough to blow the MOV on that Line to Neutral. The other reason for failure is if the park itself takes a lightning strike. Otherwise the parks substation transformer will block most of a lightning strikes effects. Same thing with houses, they don’t use Surge Protectors either.

When an MOV does ‘blow’, it’s very much like a fuse (just way more expensive to replace) in that it just sits there day after day doing nothing at all until it has to do it’s job and then it becomes totally useless and must be replaced with a new, good one. MOVs function a lot like a zener diode. They conduct no current until a specified Voltage is applied and then they conduct trying to maintain that Voltage. Zeners are usually used as low power regulators or Voltage references, but with no limit to the current through them, they will ‘blow’ just like an MOV. In fact zeners do get used just that way as protection devices for low Voltage DC supply lines like +15 Volts may have a 15.5 Volt zener between the +15 and 0 V. That protects the circuitry from a bad power supply (but a bear to troubleshoot when the machine may have 50 of them).

“Personally”, and I know I’m bucking the trend, I don’t use or believe in ‘Surge Suppression’ devices. Most if not all of the electrical devices in an RV will handle line spikes and single cycle surges quite nicely. What some of them can’t handle is ‘Modified Sine Wave’ inverters or open 50 Amp. pedestal neutrals. The Modified Sine Wave is alternating plus and minus square waves that have the same RMS value as a normal Sine Wave when applied to a purely resistive load like an incandescent light bulb or the heating element in a hot water heater. Fine and dandy until it is applied to a line operated power supply that doesn’t use a transformer but instead uses a capacitor to extract current from the Sine Wave. The Square wave causes the current to go out of site and will probably blow the device up (figuratively). The open neutral was explained previously. Imagine connecting under this condition and then turning on the TV. If the Hot Water Heater is on L2 and the TV is on L1, then the TV could get as much as 240 VAC applied to it. If it’s universally designed for 120 - 240 then you’d be okay but if it’s designed for 120 only then it to will probably blow up as well (again, figuratively).

Best bet, never plug into a 50 Amp. pedestal with and bad neutral! And how do you make sure you never do this? Either measure it with a voltmeter if you know how or install some sort of line qualifier that won’t allow connection to a bad pedestal. I use an Automated Engineering Corp. AC Transfer Switch "AECS with ESP" p.n. 10040A. They are no longer in business since they were bought out by TRC. But I understand that TRC is now making a similar device for RVs that is an intelligent transfer switch and functions similarly to the AEC device. I’ll check on this.

I hope this didn’t get too technical and that at least someone is helped with the information.

MrTransistor · 12-25-2009, 07:56 PM

Recommendations:

From TRC Technology Research Corporation
Technology Research Corporation | Electrical Safety Products

#1 Best
Automatic Transfer Switch 50A Plus
50A Plus Hardwire | Technology Research Corporation
$689.85 from Dyer's RV Catalog Number:55-2709 UPC 024098402508
$645.99 from Camping World Catalog Item # 26624

#2 Good
50A Hardwire Plus
50A Hardwire PLUS | Technology Research Corporation
$679.95 from GO-RV.com

Unfortunately, the portable models don't provide the protection of the hardwired units.

DAN L · 12-26-2009, 01:57 AM

Quote:

Originally Posted by pine tree

I just bought a Progresssive Industries Mod. SSP-50 [50 amp 240 volt] surge protector on e-bay. It looks like a good device to safeguard our 50 amp motor home. There are lights to indicate corrent wiring and polarity of the camp site electrical source and surge protection built in. The cost was only $100.00, which seems a good deal compared to other protectors that do basicly the same thing and cost much more. Best of all the device was MADE IN THE USA>
When reading the instructions, I think, I may have discovered the reason for the low cost. At the end of the fine print the instructions say - IF THE GREEN LIGHT IS NOT LIT, THE SURGE PROTECTOR IS COMPROMISED AND NEEDS TO BE REPLACED. Ouch, this sure sounds like send in another $100.00.
We are about to start out on our annual Florida winter trip in our new [used] Journey. This rig has more electrical devices and wizz bangs than the law allows, thus my desire to have some protection.
In about 10 years of RVing [Trailers and smaller class C rigs]I have not had any camp site or other electrical problems. I know however, there's a first time for everything and problem sites are out there.

Anyone have experience with the PROGRESSIVE IND. SSP-50 SURGE PROTCTOR?

Should I send it back and pop for the more expensive device or am I good to go. As I see it, the Progresive SSP-50 device is kind of like buying an insurance policy with a big deductable. Protects me from the big hit [cost] on a very unlikely event [loss] at a relatively low cost.
Some help and ideas please!!!

Pine Tree

i paid about $100 for my prog ind 50a surge protector about a year and a half ago.

i have had no problems with it.

i turn the power off at the pedestal before plugging the surge protector in. if the lights are indicating right, i turn the pedestal power off again and plug the rv power cord into the surge protector, then turn the pedestal power back on again.

Route 66 · 12-26-2009, 05:46 AM

IMO, surge protectors offer very limited protection.

Surges are rare when compared to all of the other electrical problems that can damage your rig.

Low voltage is probably the #1 problem.

An electrical management system is far superior to a surge protector as it protects against all of the possible faults.

pine tree · 12-26-2009, 10:53 AM

Thank you one and all for the help, suggestions, explanations, and ideas concerning my surge protection question. You have been very helpful to me. I will keep my Progressive Ind. device and use it as you suggest.
A couple questions of Mr. Transistor:
First, thanks for the lengthy explanation. That was a lot of work.
Second, can I check for a good neutral with one of those small [cheap two probe type] light up 120-240Volt testers? I propose to probe for voltage between L1 and neutral and then the same for L2 and neutral. I would do this before plugging the Progressive device into the Park power post to verify good neutral. Or would just plugging in the Progressive device do the same neutral check? The Progressive device does have a neutral presence light. I looked up varistor in Google,but i'm still not sure if the little light test will be effective. I sure learned a lot however. A whole new vocabulary of zeners, varistors and joules!!! As a 75 year old guy, I'll sure impress my sons with this stuff.
Third, I'm a bit confused about what you said about the RV electric hot water heater being "A low resistance device" I always think of it being very high resistance. Almost a dead short that requires an added brace to hold the electric meter down. You obviously know a lot more about this subject than me. Where am I going wrong in my thinking?
Pine Tree

MrTransistor · 12-26-2009, 03:36 PM

Hello pine tree,

No work at all, I used to teach this stuff in the Air Force so it gives me some purpose these days. Without looking at the specs. For your device, my guess is that it’s neutral detector should work as good as the tester you propose. Follow Dan’ procedure and everything should be fine.

Volts, Amperes, Ohms and Watts. The basic relationships are:

_E_
I*R

&

P=I*E

E = Voltage in Volts
I = Current in Amperes
R = Resistance in Ohms
P = Power in Watts

Many variations of these two basic formulas are used by technicians and engineers like

I2*R = P ('I2' means 'I' Squared, can't seem to get superscripts in here)

or

E2 = P (same)
R

are derived functions that are quite handy, but you really only need to remember the original two.

Whenever you can’t remember or need a different derived formula, this site is handy (unless you are a mathematician).
Useful Formulas

Examples:

A 1383 lamp at 12 Volts will have a nominal current of 1 ⅔ Amperes. 1.666 Amp. * 12 Volts = 20 Watts. It’s resistance at that Voltage and current will be 7.2 Ohms. With lamps, the resistance of the filament will vary depending on the temperature. As it heats up, the resistance increases which is a good thing since 13 Volts will increase the temperature enough to cause the resistance to increase to around 8.6 Ohms, which will yield a Wattage of just over 20 Watts. The cold filament has a nominal resistance of .6 Ohms so the initial inrush current will be around 20 Amps., more than 10X the steady state current. This only lasts for a split second since the filament heats up extremely quickly.

A 120 Watt light bulb will have 120 Ohms of resistance so that 120 Volts will produce a current of 1 Ampere. 1 Amp. * 120 Volts = 120 Watts.

A 1200 Watt Coffee maker will have 12 Ohms of resistance so that 120 Volts will produce a current of 10 Amperes. 10 Amps. * 120 Volts = 1200 Watts.

A 2400 Watt home Hot Water heater connected to 240 Volts will have 24 Ohms of resistance so that 240 Volts will produce a current of 10 Amperes. 10 Amps. * 240 Volts = 2400 Watts.

Try the I2*R with these. Same results, different way to get there if you don’t know the Voltage.

Do you start to see the relationship between the four units? I know it may be difficult for the layperson to grasp the concept but with time, a meter(?), and a little tinkering, you should start to understand what would happen if the Neutral of a 50 Amp. pedestal were to become disconnected (please be careful & have a safety buddy around if you tinker). And if you don’t, that’s okay, we are here to help. I went through Radar Sets with degreed Electronics Engineers that seemed not to grasp these [sic] simpler concepts, but they could tell you all about things like Gamma, and Transconductance.

If you have any other question, this is the place for the answer.

(last edit: trying to get superscripts and formating right)

MrTransistor · 12-26-2009, 04:06 PM

I have now looked over the specs. of the:

Progressive Industries
EMS-HW50C
Surge Protector with Voltage Protection
and Remote Display
Hardwired for 50amp RV's
Retail: $409.00
3 Year Warranty
5"W x 9½"L x 4½"H

Looks fine but I don't like the statement that if condition E-10 occurs, the unit must be replaced. I would like to see this unit with 'very fast fuses' (European ‘FF’ fuses) that would protect the MOVs and be easily replaceable. Other than that, this unit should work fine for all RVs.

Why don't the RV manufacturers install something like this or the TRC device at the factory? It may not be perfect but it's better than no protection at all!

MrTransistor · 12-26-2009, 04:11 PM

If you don't need the remote, I suggest this one with the same comments.

EMS-LCHW50
Surge Protector with Voltage Protection
Hardwired for 50amp RV's
Retail: $349.00
3 Year Warranty
5"W x 9½"L x 4½"H

pine tree · 12-27-2009, 05:00 AM

Thanks again everyone. Our new [used] Journey has an EMS built in, so I think we are good to go. The progressive device will be used as a pre-plug-in camp electric supply checking device. Sort of like, just to be sure all is well.
Mr. Transistor,
WOW, I will print what you sent and study it. Bottom line however, I think I will stick with fishing. We have hard water [ice] here in Minnesota and the sunnies are biting. Wife and I [54 years and counting] always have fun.
Thanks again,
Pine Tree

nsdienes · 12-27-2009, 09:14 AM

Quote:

Originally Posted by pine tree

Thanks again everyone. Our new [used] Journey has an EMS built in, so I think we are good to go. The progressive device will be used as a pre-plug-in camp electric supply checking device. Sort of like, just to be sure all is well.
Mr. Transistor,
WOW, I will print what you sent and study it. Bottom line however, I think I will stick with fishing. We have hard water [ice] here in Minnesota and the sunnies are biting. Wife and I [54 years and counting] always have fun.
Thanks again,
Pine Tree

Just in case and tell me if I am wrong. The EMS provided in Winnebagos is used only to shed devices in a prearranged order if the RV uses more than 20 or 30 amps as set on the remote. It offers no additional electrical protection.

McDuff · 12-27-2009, 09:21 AM

I can attest to "no additional protection". Last July 4th, we got a lightning strike surge during a storm. Took out my EMS board, my a/c control board, my satellite dish, and my holding tank sensor control board.

I'm looking into the Progressive Ind stuff, and will probably go whole hog and get the portable PT50C, it also seems to have the highest joule rating for portables.

Route 66 · 12-27-2009, 09:23 AM

Quote:

Just in case and tell me if I am wrong. The EMS provided in Winnebagos is used only to shed devices in a prearranged order if the RV uses more than 20 or 30 amps as set on the remote. It offers no additional electrical protection.

I believe you are correct.

MrTransistor · 12-27-2009, 12:55 PM

Correct.

pine tree · 12-28-2009, 09:04 AM

OK, I understand. The EMS is in danger, not in protection. I just gave my new Progressive Ind. SSP-50 a big kiss. It's not plugged in. Anyway, with all your help the device seems to be just what I need and want. Fairly good protection, maybe not the very best, but also at a fairly low cost. Just like the rest of my insurance. I am very gratefull for all your help.
Pine Tree

Barrier2 · 02-18-2010, 11:10 AM

These explanations are really great, I was also confused about the various types and choices of hard wired vs portable.
I do have an additional question that might help others. I suppose the wired in version seems to be the best choice. My 2001 Dynasty has a power cord reel for the electric line which seem to be common. Is it hard to use the wired in version in conjunction with a powered reel?
Robert

Wayne M · 02-18-2010, 06:22 PM

EMS = Electrical Management System. It manages the electrical in the coach so that you do not "overload" the circuit when on anything less than 50 AMP. If on 30 amp and you need cooling, it will manage compressor 1 and 2, and the microwave, etc., It will turn off what is necessary to provide electricity to what you are using. At least that is the way I understand it. It is not a surge suppressor.