ISB Sola regulators

[Tequila]

Some info and a question. First of all I have created a chart with the specs for the ISB Sola 4000 & 8000 compared to the Hughes 30 and 50 amp autoformers. Here it is https://www.mexicocaravans.com/ISBvsHughes.pdf

Now the question. Has anyone wired up an ISB Sola 8000? Are there separate terminals for the 2 hots in a 50 amp cable, or do you strap them together?

I do have wiring instructions for the ISB 4000 here: https://www.mexicocaravans.com/Regulator.pdf

[rocmoc]

Regarding 50amps. We have a 50amp Motorhome, fortunately with just the basic old style power switch box at the entry point in the side bay. We have never had a problem using just 30amp in Mexico. You have to manage your usage and only one AC unit at a time if at all. We carry a couple of fans with us that move the air when needed. We use the fans even when connected to shore power. Our Sola Basic is wired into a 30amp cord and use an adapter at the male end of the 50amp cord. Never a problem! We do carry an extra switch box and Progressive Surge Protect with us when and if needed. As a point of interest when we were staying in Villa Corona Mexico a few years ago, a Huge Motorhome arrived with a Caravan. This rig had 3 (THREE) AC units and had the AC on the entire time. Never checkout how they were doing it, just thought it was weird at the time as we never turned ours on the entire stay. For those who have never been to Villa Corona, cold is be more of an issue than heat.

rocmoc n SouthWestUSA / Baja&RockyPoint next winter

[Tequila]

I notice mercado libre sells them

[pianotuna]

Tequila,

I've now "tweaked" the Sola Basic to "cut in" at 113 volts. It is a little better fit than 110 and boosts iirc to 122 volts from 113.

[Tequila]

This has come up again with a customer. RV 50 amp is really 2 30 amps split between 2 different zones on the RV, A 50-30 amp adapter does bridge the 2 halves of the 50, but ONLY FROM the point of the RV, not the pedestal. A 50-30 amp adapter It is designed to plug into a 50 amp pedestal where it only picks up 1/2 of the circuit it then bridges the 2 inputs from the point of view of the RV..If it bridged the 2 halves at the pedestal end which are out of phase, it would trip the breaker..

Therefore the only way to get true 50 amps at the RV is to use 2 ISB 4000's and an an 50 amp adapter cable splitting the 2 phases, one to each of them. A big headache unless you have room to wire 2 of them permanent into the rig.

In other words buy the 4000.

[pianotuna]

Tequila,

80 x 120% ~= 96 volts. I guess at that voltage one is pretty much hooped. That leaves generator for large loads and solar for low loads.

[pianotuna]

CA Traveler wrote:
I think pianotuna got one with some skullduggery (just kidding) and it's served him well for 30A. If the device was available in the US/Canada I suspect there would be more posts.

One of the Canadian members kindly offered to transport one for me from Mexico. It was kind of he and his wife to do so.

[CA_Traveler]

Back in the day when pianotuna started posting about the Sola device which had both buck and boost capability I wanted one for my 50A RV but that was not available.

I think pianotuna got one with some skullduggery (just kidding) and it's served him well for 30A. If the device was available in the US/Canada I suspect there would be more posts.

[Tequila]

pianotuna wrote:
Tequila,

Are you saying the shore power source is not fused or has no circuit breaker? I can't see how adding an additional breaker--if there already is one would help.

Thanks for posting the chart--it is where I did the math from for the buck and boost percentages. So it is buck of -10% (135 volts), boost of +10% (110 volts) and additional boost of +20% (100 volts).

The buck is a calculation only. The boosts were checked by actual measurements, but under no load.

BTW the lowest voltage I've measured was 99 under no load and 97 under load from air conditioner. The Sola basic allow me to cool down my RV safely.

Based on the fact the 8000 does not have 2 hots, i see little reason to use it rather than a 4000. I have had voltage drop to 80 volts on one occasion.

[moisheh]

As Tequila mentioned 50 amp services is rare. Even then it may not be a real 50 amp service or the wiring is not very heavy. I would never hard wire that devic device. Risk of fire. Even th Hughes autoformer is risky. Some campgrounds do not allow that device. Connecting a modern motorhome in Mexico is always risky. Lots of electronics that are voltage sensitive. John and Angela are no longer active in this forum. He was travelling with a 30 amp smaller Class c. When the voltage was low he had a smart charger that would run on low voltage. I think it was 90 volts. He would plug that into the shorhe power. No worries.

[pianotuna]

Tequila,

Are you saying the shore power source is not fused or has no circuit breaker? I can't see how adding an additional breaker--if there already is one would help.

Thanks for posting the chart--it is where I did the math from for the buck and boost percentages. So it is buck of -10% (135 volts), boost of +10% (110 volts) and additional boost of +20% (100 volts).

The buck is a calculation only. The boosts were checked by actual measurements, but under no load.

BTW the lowest voltage I've measured was 99 under no load and 97 under load from air conditioner. The Sola basic allow me to cool down my RV safely.

[Tequila]

OK just checked it out, you are correct. So unless the 8000 handles 2 hots separately there is no advantage in buying the 8000/ Learned something.

[Tequila]

CA Traveler wrote:
The 50(male)/30 adapter connects one 50A hot to the 30A hot.

The 30/50 adapter connects connects the 30A hot to both 50A hots. This is a connection that does not trip the pedestal CB so it's not a short in that sense.

What happens with a 120V sola device is dependent on how and where it's installed. Hardwiring inside a 50A RV has potential issues when it's later plugged into a 120/240V 50A plug. The devil is in the details.

I would like someone to check it with a meter. The wiring diagram i see on net, shows the hots as bridged. I may have one out in my Rv, I will go check it with an ohmneter. You may be correct.

[CA_Traveler]

The 50(male)/30 adapter connects one 50A hot to the 30A hot. The other 50A hot is not used. The RV is limited to 30A by it's 30A CB.

The 30/50 adapter connects connects the 30A hot to both 50A hots. This is a connection that does not trip the pedestal CB so it's not a short in that sense. It provides 120V everwhere in the RV with a total draw limit of 30A.

What happens with a 120V sola device is dependent on how and where it's installed. Hardwiring inside a 50A RV has potential issues when it's later plugged into a 120/240V 50A plug. The devil is in the details.

[Tequila]

CA Traveler wrote:
If they add a 50A CB to the input then they will be OK provided nothing in the RV limits the power. My rig and others have load shedding which would not detect 240V and load shed to the default 30A. This cannot be changed w/o rewiring. In Mexico without a 50A CB on the SOTA and if they are drawing 8000 va which is 67A then the neutral from their 50A power plug to the CB panel is overloaded by 17A.

A hardwired unit would have to be removed upon returning to the US because the shorted hots will blow the 120/240V 50A CB.

Many years ago I concluded that the least understood topic on any RV forum was electrical and the least understood electrical item is 120/240V 50A power. Just shows how little is known about home power which is the very same circuit except the CB panel will have a 200A rating for example.

You're giving them good advice IMHO but they don't understand how different a 120/240V circuit is from a 120V circuit.

Thanks for that info. I am not so sure the shorted hots would trip the CB since a 50 amp to 30 amp dog bone shorts them anyway. I have used one in a park that only had a 50 amp socket to plug my 30 amp rig into. Tres Amigos in mazatlan which only has 50 & 15 amp on some pedestals. Whether it is really 50 amp is debabatable. I have only seen 50 amp in 2 other parks in Mexico. Telaquepaque in Lo de Marcos and Arturos park in Cuitzeo