A/C Power Selector Switch schematic ?

[AppliedThinking]

Does anyone have a location or drawing for the A/C source power selector switch? Our rig is a 98 Gulfstream SunSport with a 30amp shore power connection and Generator.


Traditionally, with the old Coleman Mach A/C units, one had to run the generator for both front and back A/C units to be used. Or, only one at a time with shore power. You can run one A/C with shore power and the other with generator power in times of need.


It is time to replace the old rooftop A/C units and the new units are very power efficient. Enough so, that one can run both front and back on a single 30amp shore power connection. I have no desire to fight the power selection switch, Thermostat time delays with these new efficient units in place. It's time to rethink the A/C power selection wiring. Yes, I will measure the amperage to validate the draw with the new units.


We are also including Heater strips in the new A/C units. Hopefully bypassing the central propane heater system with something more efficient. Will also validate the amperage draw during the heat cycles.


If anyone knows of a drawing source, I would very much appreciate it. Thank you in Advance!

 

[finallygot1]

Are you referring to the switch front/rear for your air units?

 

[Bike Dr]

Hello Your situation sounds odd!

First can run any one of the two A/C units when you are hooked to shore power?
And the same with the generator?
Did someone alter anything in th coach?
My first thought is if that is the case then is your transfer switch working correctly!
You will definitely want to know as to not have a problem when hooked to sure power and running the generator at the same time the transfer switch is supposed to isolate the two incoming power sources to operate off of one or the other.
My transfer switch is located in the rear under the master bed..

LIFE IS GOOD!!!! LIVING IT!!!!

2005 41'4 ATRIUM SE CAT
2017 20' Diamond closed trailer
2014 Streetglide Special
2010 Mini Cooper or 04 H2

 

[AppliedThinking]

Yes, the switch is located under the rear master bed, front of the water tank.
Today, I plan to reverse engineer the A/C power selector switch and distribution panel prior to any changes. Lots of pic's.

 

[AppliedThinking]

These old GS rigs were designed for 30amp shore power, However, the generators are 5.5-6kw. The old Coleman Mach AC units were not that efficient, power consumption wise, and hence only one AC unit(front or back) could be run when only using shore power. With the generator on, both front and back AC units would work. However, there was not much room power wise for anything else. At one time, we did blow the generator regulator out when my wife decided to vacuum when we had both units trying to cool down the RV. Right at the start of the camp site reservation. Not good.


So with the generator in mind, one would think that the distribution panel would be rated at least 6kw. This is 1/2 of a 50amp 240vac service (single hot lead). If so, then I might entertain upgrading the shore power and just rewire the switch to shore or generator supply. If the power distribution panel is rated at 30amps then I will have to consider changing it out.
The Furrion AC/Heater units are so much more power efficient compared to the old Coleman's that I may have a simple solution. In any case, I will fully understand the circuit first before moving forward.
The 98 rig has less than 16k miles on it. Lots of life left in the old girl.

 

[AppliedThinking]

I did want to say thank you for the input. I will keep things posted as I move forward.
Very Best Regards

 

[Bike Dr]

Thanks for the added information!
I look forward to hearing how you reconfigure your older coach to work for you. I am a fan of the older coaches as well as new technologies and innovation. I am a gadget guy for sure. Like you I purchased an older coach with low miles that had its problems. it has been a fun project bringing it up to today's tech. If you have some pictures I would like to see your ideas and progress on your coach as you go along.
I am a mechanical tech with many skills but far from a rocket scientist.
Good luck! And I will help in any way I can if needed.

LIFE IS GOOD!!!! LIVING IT!!!!

2005 41'4 ATRIUM SE CAT
2017 20' Diamond closed trailer
2014 Streetglide Special
2010 Mini Cooper or 04 H2

 

[AppliedThinking]

Had a little time to start taking apart the power selector (crossover) switch in the RV.
Turns out to be a Kraus & Naimer CA10 A300 and there are some switch wiring diagrams on the internet.
Definitely different pole numbering positions. It will take time for me to digest.
However, it is pretty simple, two input powers (Shore and Generator) and two output selections (Front and Rear AC).
I think that I see how the Generator power goes to both AC units as there is a jumper on the hot side that links another switch layer.
Just started to map things out and take lots of pic's.
The good news is that the AC distribution panel is already at 50amps. The AC has a 20amp breaker for both units. Which is good since the switch is rated at 20amps as well.
That means that all I have to do is connect one leg of a 240vac 50amp connector and the RV will have 6kw shore power. I had already upgraded the shore power cable.
I could also build a 30amp to 50amp adapter but most, if not all, campgrounds have 50amp service. The rear compartment internal connection from the generator to the shore power line may need attention as well. Still simple.
Then all I need to do is put in a jumper in the shore power input, just like the generator power input, to the switch and use both AC units with either power input.
That is the plan at the moment, until I get everything mapped, tested and validated before making any changes.

 

[Bike Dr]

Hey there you go that's what I like to hear dig right in.
I stared to mention upgrading to a 50 amp to have the option. no need to make a 50 to 30 amp adapter or vice versa. They sell them all day long. Just look for quality made adapters, I used to make them up but found it was no cheaper then then just buying it now days. Glad to hear your transfer switch is rated at 50 amp. The only circuit I have that is not on the Gen is the washer/ dryer combo and the block heater. You will be much happier once you get the 50 amp. But i still do run into 30 amp only hookup at times. At that point I will only run one ac at a time worst case and seems to keep up nicely. I switched out the 10 gal water heater to a tankless and it also lightened up the load draw. No more heating elements.they only need a 12v to operate No more two minute showers! If she is doing dishes and I am in the shower it no longer an issue to have to think about it anymore. I just changed the 120v circuit in the basement storage from the old water heater and put a receptacle in its place for extra power if needed..
Thanks for the update!!

2005 41'4 ATRIUM SE CAT
2017 20' Diamond closed trailer
2014 Streetglide Special
2010 Mini Cooper or 04 H2

 

[AppliedThinking]

Ok I got the time to reverse engineer the two sources (actually 3 sources with a 30amp and a 20amp from the Generator) and the shore power at 30amp.


In a non-generator mode (shore power) 30amp will come into a junction box that sits in the water tank box under the bed. That line splits into a 20amp circuit and the balance to the coach), The 20amp circuit goes through a CB to pins 7-11 on the AC power switch. Output is either pins 8-12 Rear AC or pins 2-6 Front AC (there is a jumper going from pin 6 to pin 10).


In a Generator (both front and back AC) mode, the 30amp circuit goes out the via the internal Gen connection and back into the same junction box. Pins 7-11 which feed the rear AC. The front AC is fed by a dedicated 20amp generator feed pins 1-5 which feed the front AC pins 2-6.


From here, I will figure out how to combine front and back AC units via shore power line. Most likely by changing over to a single pole on a 50amp connector which will give me max 6kW into the junction box. Will have to do some wire calc's to stay out of trouble.

 

[THenne1713]

MY understanding why/ how was MOST camps ONLY had 30a and 20a in older days, some rigs added 2nd unit and switch option of which would run on 30a power center; (some now switch with selector), some no switch, you could run dedicated 2nd unit on a separate 20a cord that ONLY supplied that Air unit? Hope this helps?

 

[AppliedThinking]

Well that is certainly an option, It would require a second umbilical power connection.
I am still leaning toward using a single leg (L1) from a 50A 240vac supply. I just double up the red/black wires in a 10/4 power cable for the power leg leaving the white (Neutral) and green (Ground) leads to the appropriate pins/socket assignments. This method has served me well in the past.

A simple 20A double throw switch, next to the AC power selector switch, can give me the needed isolation, if I ever need to use a generator for both AC units. These new units are so power efficient that I could most likely use just a 30A source and be smart what is turned on while both units are cooling. However, I will make a bold statement that a single leg of a 50A circuit will give me 6kW to play with while the standard 30A is only 3.6kW. Once again, my A/C distribution panel is rated at 50A.

 

[AppliedThinking]

Continuing on, completed the 50A (one leg) shore power to 30A adapter. Yes there are versions of this on Amazon but wanted to insure the single leg. I used a 6ft length of 10/4 power cable running the red/black pair in parallel.


Decided to install a current/AC volt meter in the shore power supply line. Chose a DROK AC Meter, AC 80-300V 100A Voltage Current Power Factor Frequency Electric Energy Monitor Ammeter Voltmeter Multimeter Tester 110V 220V Digital Color LCD Volt Amp Watt Detector Reader Panel for the sensor. I will have to slightly extend the CT leads from the J box to the meter unit. Will mount it in the same area as the existing power distro panel and, soon to be, a 20A bypass switch for the front AC unit.



The 20A bypass switch will be located near the Front/Rear shore A/C selector switch. Wanted to incorporate a separate 20A breaker however, there is no available room in the existing distro box. The next best thing would be a single pole switch with a 20A breaker built in. (eg. TE CONNECTIVITY/POTTER & BRUMFIELD W31-X2M1G-20 Circuit Breaker, Thermal, 1P, 250V, 20A) which are not available to my knowledge. There is a Tyco w31-x2m1g-20 version with the same spec's. 2 week or more shipping time. In the mean time, I am going to use a double pole light switch with a inline fuse for safety. I have a bunch of TTHN 10awg wire for the bypass. Incoming tap will be the RV side of the incoming shore power line after the CT. The other side of the switch will be the hot and neutral legs for the forward A/C unit. 95% if the time, we will be using the shore power and not the generator. In that case, will leave the 20A circuit breaker/switch on the Generator to the off position. The bypass switch will provide power to the Front A/C unit while the 30A side of the shore power will provide power to the Rear A/C. Online example show a 12A draw for each Furrion A/C unit during operation. There is a short slight in-rush current at A/C startup so I will stagger the power on between the two. The Furrion 15kHE have a special startup capacitor to reduce the initial in-rush current.


As stated by someone else, this is just typical power management. Will most likely set up a quick reference card that will be in a pocket near the power distro location. Since my family is non-technical I hope to keep things simple (KISS).

 

[AppliedThinking]

Ok here are some lessons learned:
Rewired the incoming shore power line to include a Coil Tap (CT) for a Drok multi-meter that shows incoming Amps, Volts, Frequency and more. Since I tied both #10 red/black in parallel (which gives me an effective #7 gauge) decided on using a heavy duty butt splice vice a blue wire nut. It was an extremely tight spot to get the crimper in place let alone squeezing the bolt cutter line handles. Oh and it was impossible to see as well. Got it done but took several passes to work the butt splice down.
Wired in the CT and voltage tap for the Drok meter. Used a shielded 20 gauge 4 conductor wire for the sensors. Worked perfect!
Also added the new 20A 2 pole switch to the incoming shore power connection for the Front A/C unit. Cannot leave the A/C unit connected to the Front/Rear selector switch or it will feed back in to the distro box and pop breakers. If desired, the fix would be to change the 20A switch to a DPDT On-On switch that would allow me to select the source power. Since we never get to a situation were we need to run both A/C units via the generator, I just opted to disconnect from the main selector switch and hardwired the new Front A/C switch. Now I can run both A/C unit while using Shore power. I will look for a DPDT On-On 20A switch at a later time.

This is where the new Drok multi-meter comes in. One A/C unit draws about 13.1A. Together they draw 26.2A While the RV is cooling down. So yes, both A/C units can run on a 30A circuit. If one pays attention!! (eg. Don't plug in that vacuum cleaner or start the microwave with both units on while on a dedicated 30A Shore power.). For me, I am using a single leg of a 50A Shore power source. That's plenty of room for both A/C units and then some to spare.


One step forward....

 

[AppliedThinking]

Yesterday, I completed the new Furrion 15kHE A/C unit install. Part of that install was to design a mini Manual Transfer Switch (MTS) that would allow both units to be used at the same time connected to Shore power. The MTS is either in Shore or Generator mode. Gulfstream has a A/C selector switch that only allows one unit to be used at a time when on Shore power because of the older Coleman Mach current draw while connected on a 30A Shore power service. I would like to report that I have made power measurements of the Furrion 15kHE and they appear to max out at about 13.86A during high fan speed cooling (round off up at 14A). All measurements, current and voltage, were taken with an inline multi-meter with a Coil Tap (CT) and primary Shore power Voltage and Frequency tap.





Part of that incoming Shore power rewiring was to pick a single leg off a 50A Shore power service. All cables have been upgraded for 50A single phase. The Distribution Power Panel is already rated at 50A. While the new MTS switch is selected for Shore power, the Forward A/C has a separate 20A breaker in line. In Generator mode, the MTS supply power comes from the 20A breaker on the Generator. With both A/C units running on Low Fan speed, the current draw is less than 28A. With a primary 50A source, that's plenty of room to run other electrical appliances (eg. refrigerator, AC to DC converter, and microwave). I should be clear in stating that there were no changes made to the new Furrion A/C units. Only the incoming Shore power distribution.



With all this said, we are ready to head out this coming weekend with two working new A/C units with the original Coleman Mach control boxes. The Heat Strip elements are installed. The Heat Strip power line is secured waiting for the right Furrion Control Box. We certainly do not need heat during 100F weather outside.


Apologies for being so verbose. Well aside from the wrong FACC10SA-BL control boxes this has a positive outcome that will work for now. I will draw up the incoming Shore power with MTS for future wiring reference. It will be available if you wish.


Time to close this thread as completed.

 

[Bike Dr]

Thanks for keeping us updated as to how things were coming along! Good luck on your trip this weekend. I like to hear how projects work out.
Take care be safe and happy camping ��

LIFE IS GOOD!!!! LIVING IT!!!!

2005 41'4 ATRIUM SE CAT
2017 20' Diamond closed trailer
2014 Streetglide Special
2010 Mini Cooper or 04 H2

 

[AppliedThinking]

Here is a very rough draft of the wiring diagram (attached).
The "Use are your own risk" is provided for consideration.
This is how our rig is currently configured.


I can state that working under the rear master bed was not fun by any means. All high current connections were done with heavy duty butt splices. Getting bolt cutter line crimp tool to work was an absolute pain in the tail. Not to mention your almost working blind. I would recommend using an electro-hydrolic crimping tool a much better choice. Lesson learned!


09jul24 - updated draft drawing to v2.0 - Included Drok power multimeter and indicated some power flow direction arrows.

 

[AppliedThinking]

For those who have gone cross-eyed with the schematic. Here is a much simpler view of the final product (minus the safety toggle switch covers).