Forum

Advertisement




Notifications
Clear all

Question SoftStart

 

 David Eberly
(@David Eberly)
Guest
Joined: 3 weeks ago
Posts: 1
Topic starter  

Mike,

Regarding the New SoftStart, apparently it is mainly for 30amp use. We are Class A 50amp users and only once took a 30amp site. Is there SoftStart benefit when plugging into 50amp?

Is the SoftStart a 30amp plug in only there for requiring a reverse dog bone?

David


QuoteSolved
(@mike)
Moderator
Joined: 5 years ago
Posts: 111
 

The 50-amp version should be available in January. I'll post as soon as I have a definite date. 


ReplyQuote
 DAVID CALKINS
(@DAVID CALKINS)
Guest
Joined: 2 weeks ago
Posts: 1
 

What would be the benefit of a 50 amp version?  Would it be to let the AC unit and the refrigerator to slowly ramp up and minimize the amperage draw down resulting in lights plugged into other circuits from dimming, etc.?


ReplyQuote
 Dan Blais
(@Dan Blais)
Guest
Joined: 1 week ago
Posts: 2
 

I purchased and installed two compact SoftStart modules in our Dometic rooftop air conditioner units about a month ago. Until recently, we haven't had the opportunity to test the SoftStarts using 30A service.

A few days ago we stayed at a park that only had 30A service; so we tested the SoftStart by running our two 15K BTU A/C units and it worked! But, doing so caused us to pull all 30A available from the power post just to run both A/C units. I use a Hughes 50A Autoformer when connecting to shore power, including to 30A service.

We have an all-electric coach, so doing anything other than running the A/C units (like using the induction cook-top or the microwave or the residential fridge) means we'd have to shut one of the two A/C units down.

When breaking camp the next day, I noticed that one of the blades on the 30A dog-bone to 50A plug to the power post was burnt and the insulation at its base was starting to melt. The air conditioner test on 30A circuit lasted less than five minutes - but it looks like the dog-bone couldn't handle maximum 30 amps for extended periods.

So, what's the point of trying to run two air conditioning units if you're ultimately going to fry the 30A side of the power cable? Are there any 30A to 50A dog-bones that can handle the increased current for extended periods?

 30A Plug After SoftStart w 2 air conditioners

ReplyQuote
(@mike)
Moderator
Joined: 5 years ago
Posts: 111
 

Remember that the SoftStartRV technology only helps reduce the inrush current when the compressor starts up. It does nothing to reduce running current. So if you have a pair of 15kBTU air conditioners you can be pulling very close to 30 amps. But that doesn't leave any headroom for other electrical appliances and you'll need to shut off one air conditioner if you want to run an electric appliance. That's the reality of trying to power an RV from a 30-amp circuit that can only supply 3,600 watts. Be aware that a 50-amp circuit can supply 12,000 watts which is a big difference. 

As far as your 30-amp plug meltdown, that was most likely caused by a poorly maintained pedestal outlet, not your own plug. Essentially, your 30-amp plug was damaged by a worn or oxidized pedestal outlet. But campgrounds will rarely admit that. 

While UL does rate the TT-30 connector for 30 amps continuous current and tests them at 125% of rated load (37.5 amps) for extended periods with only a minimal temperature rise, their testing assumes the pedestal outlet contacts are clean and tight. But that's not always the case in older campgrounds.  

Sadly, campground outlets lead a rough life and are rarely maintained properly. I've been trying for the last 5 years to get a campground association to let me create training videos on how maintenance and testing could be safely done by campground maintenance crew, but so far I haven't even had a nibble. That's why if's up to every RV owner to visually inspect any pedestal outlet for signs of damage or wear, and if it feels loose when you plug into one call campground maintenance immediately and ask that it be replaced.  


ReplyQuote
 Dan Blais
(@Dan Blais)
Guest
Joined: 1 week ago
Posts: 2
 

@mike Thanks for the explanation on why my 30A to 50A dog bone adapter overheated and the 3600 watt limit on 30A sources.

That brings me to a another question - would  changing out my Magnum MS 2812 Pure Sines Wave Inverter for Magnum's hybrid MSH3012RV 3000W 12VDC Pure Hybrid Inverter Charger allow the hybrid inverter to draw power from the battery bank when running two air conditioners on a 30A pedestal and we need to microwave something or the residential fridge turns on, etc?

I think this hybrid can be configured to start the generator when power consumption gets near the limit of the input shore power. But, I'd prefer to prioritize the house batteries supplying power before resorting to starting a generator during quiet hours in an RV park.

We have four 100W solar panels on the roof which would be used to assist in recharging the batteries after a short term increased amp draw pushes the total current above 30A - if the hybrid inverter works this way, it could prevent tripping a 30A circuit breaker.

The last time I check on the internet, the 3012RV 3000W inverter retailed for around $2,200. Yikes!

 


ReplyQuote
 Patrick Brown
(@Patrick Brown)
Guest
Joined: 1 week ago
Posts: 1
 

Your picture shows this device plugged into shore power source. Can it be plugged into a portable generator?


ReplyQuote
 Sharon B
(@Sharon B)
Guest
Joined: 4 hours ago
Posts: 1
 

I have a 50 amp 5th wheel.  Can I ever use a 30 amp for my rig? Will it fry my plug or damage my rig?  So will I have to wait until your 50 amp plug is available for the soft start?


ReplyQuote

Leave a reply

Author Name

Author Email

Title *

Maximum allowed file size is 10MB

 
Preview 0 Revisions Saved
Share:

Advertisement