Hydraulic Pump Breaker Upgrade

[GreG L.]

I would think that breaker tripping won't be much of a problem in the summer months when the hydraulic fluid is nice and warm and thin, but winter does come around once in a while.

[BB_TX]

It can happen any time. At least on ours. We typically have only used ours between April and October. And before I changed out the 50 amp breaker it would trip even in the summer months in TX.

[Mikendebbie]

When we get back home I intend to install a Magnum 125 amp in-line fuse on my inverter line (that BB found on amazon for me - less than $50) and move the 80 amp breaker over to serve the pump. I will post pics when it is done with notes to hopefully help the next "chimp in space capsule" like me.
This thread has helped me a bunch!

[glendodom]

Originally Posted by Mikendebbie

I have a 2018 model and I am confused like the original poster. My issues started in month 11 of ownership. My unit had a 50 amp (black) manual reset breaker on the red wire going to the inverter switch (round red/green switch in the pics below). Carl’s pic is of a 2019 and it shows a magnum fuse in the same position as my OEM 50 amp resettable CB. This CB is the thing on my unit that was tripping during hydraulic system operation. I replaced it with an 80 amp CB and tightened all connections in the front compartment (because I did not realize it was the inverter wire not the pump wire)and fortunately had no issues until July 4th weekend when the system tripped. The 80 amp on the inverter line tripped first and I went out and reset the blade switch. Then the hydraulic system “paused” (tripped) but reset itself and continued to operate. This tells me it was the OEM 50 amp auto reset CB to the pump. It is the red capped item on the left. In the second pic you can see the red wire going from the red capped breaker on the left to the pump. I ordered another 80 amp CB yesterday and will replace it this week before we leave this weekend.

I don’t understand why the CB in the inverter line has been tripping - the OEM 50 amp and the replacement 80 amp. Again - I replaced the 50 amp on the inverter line because it looked just like the pics that have been shared in the many threads about the hydraulic system tripping (translation: I replaced it out of ignorance and luck I suppose). I did not know what those 2 little red capped things were. However I am not going to reinstall the OEM 50 amp CB...generally things are better now than they were in December.

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I spoke with the Keystone/Montana Owners Customer Service today about the question of the T-Fuse strip on the inverter line versus my trailer originally having a 25 amp breaker. She advised since I was only running a residential refrigerator that the 25 amp breaker was all that was required versus the T-Fuse strip? I guess that means if we wanted to do otherwise we are on our own!

[glendodom]

Reference the question of upgrading the hydraulic pump breaker from a 50 amp to the 80 amp breaker, I spoke with the Keystone/Montana Customer Relations Div today and discussed my continued issue of the slides causing In-Command system to basically shut off and reboot advising her I had seen where Lippert had a paper out advising of upgrading to an 80 amp breaker. She advised that they didn't show any such advisement from Lippert. She advised I could take it in to a shop and have them submit a technical issue with the situation for their evaluation. CW had already called themselves upgrading my breaker but had actually upgraded the inverter line breaker instead. I may be to the point of just doing it myself. Seems to be a losing battle getting the point over to both CW and Keystone!

For clarification, the picture attached of my wiring the breaker in the middle is the one where the wire feeds up to the hydraulic pump. As noted within the picture the original breaker doesn't look like the breaker to the Busman breaker to the left which feeds the inverter but as I understand Lippert advises to upgrade with a Busman 80 Amp breaker which looks like the one on the left. Correct?

[Mikendebbie]

The sketch I included on post #10 above was wrong and I have tried to doctor it up a bit below. I labeled some items A B C and 1-2 for reference.

I intend to call magnum again and quiz them for the correct size fuse to install on my inverter line (A).

I intend to install an 80 amp breaker for my hydraulic pump in position (B). If you look at the breaker in the sketch on line A and how it is oriented with 1 on top and 2 on bottom - the 80 amp breaker on line B will have the wires at position 1 on top (electrical current out) and the wires at position 2 on the bottom pole of the breaker (electrical current in). I am told I will need to drill out the connections for the small red wires to get them to fit the breaker pole.

[Last2Die]

Does anywhere know where to find the inverter for a 2018 3920. I don’t think I have ever seen it... I think on my unit it only charges the batteries.

[glendodom]

Originally Posted by Last2Die

Does anywhere know where to find the inverter for a 2018 3920. I don’t think I have ever seen it... I think on my unit it only charges the batteries.

You may be getting converter and inverter confused. The converter charges the batteries. Your inverter is converting 12V to 120 AC for operation of the refrigerator during travel. The inverter on my unit is mounted in the storage compartment on the driver side up in the top (front left side). The converter is within your panel system with the RV entrance way. The 3721 has the residential refrigerator with an inverter. As I understand it the 3720 doesn't have a resiential refrigerator thus I presume it wouldn't have an inverter.

[Last2Die]

Originally Posted by glendodom

You may be getting converter and inverter confused. The converter charges the batteries. Your inverter is converting 12V to 120 AC for operation of the refrigerator during travel. The inverter on my unit is mounted in the storage compartment on the driver side up in the top (front left side). The converter is within your panel system with the RV entrance way. The 3721 has the residential refrigerator with an inverter. As I understand it the 3720 doesn't have a resiential refrigerator thus I presume it wouldn't have an inverter.

You’re right. I figured I did get them both confused. The converter is behind my fuse box right..? My 3920 has the rv fridge.

[Al & Sheila]

Originally Posted by Mikendebbie

The sketch I included on post #10 above was wrong and I have tried to doctor it up a bit below. I labeled some items A B C and 1-2 for reference.

I intend to call magnum again and quiz them for the correct size fuse to install on my inverter line (A).

I intend to install an 80 amp breaker for my hydraulic pump in position (B). If you look at the breaker in the sketch on line A and how it is oriented with 1 on top and 2 on bottom - the 80 amp breaker on line B will have the wires at position 1 on top (electrical current out) and the wires at position 2 on the bottom pole of the breaker (electrical current in). I am told I will need to drill out the connections for the small red wires to get them to fit the breaker pole.

I added a relay on Monday and the wiring was slightly different than what you show. The terminal on mine where the larger wire feeds the hydraulic pump has two large wires, one for the pump and the other goes into the coach and I assume lands at the converter.

[jcurtis934]

Inverters are rated in watts, fuses and circuit breakers rated in amps. 1000 watt inverter, 150 amp non resetting circuit breaker or fuse. 2000 watt inverter, 300 amp circuit breaker or fuse.

[Mikendebbie]

I installed an 80 amp breaker on the hydraulic pump system this morning but it feels like the wiring is backwards. Look at my pic of before and after - before on the bottom. It does not seem like the big red wire going directly to the pump is protected (the sort of orangish-red wire going to the right and up). The other big red wire on the bottom pole is the battery lead.

The top pole of the breaker is the protected side, correct? Do I need to reverse the wiring and put the little wires/single big red wire with black tape on the bottom + both big red wires on the top pole? (By the way -the before pic is not mine but mine is identical. My pics were a bit too out of focus so I borrowed that one).

In the before pic - is the copper pole the protected pole?

[Al & Sheila]

Mikendebbie, the copper terminal is battery positive and the terminal on the left is protected and feeds the hydraulic pump motor and also the battery positive into the RV. The fusible links don't care what side the positive is on as they heat up and open on high current.

[Mikendebbie]

Ok - so if the 2 red wires on the left are protected - the they need to be on the top pole of the 80 amp to be protected - correct?

[Al & Sheila]

I dont think it matters on the 80 amp unless one side is marked line + and the other load but dont remember seeing that.

[Mikendebbie]

I have posted this before - but my unit came with a 50 amp breaker (just like the 80 amp in the pic) on my inverter line. I intend to get an inline fuse like in the 2nd pic. That 50 amp breaker is definitely “in” from the battery on the bottom pole and “out” to the inverter on the top pole- so the top pole is definitely protected.

[glendodom]

Attached is a picture of my 3721RL as it was original wired. The two small wires are hooked to the connection with the battery input, not on the output side. My new 80 amp breaker was marked/noted "BAT" and "AUX", thus all the wires coming from the hot side/battery to include the 2 small wires hook to the "BAT" terminal.

[Mikendebbie]

I went and looked for the BAT marking and my wiring in the photo is correct. Thank you Glenodom!

Additionally (and best of all!) - when I hooked everything up - it worked!

[Texan]

Those that are reluctant to change from the 50 amp to 80 amp breaker need to remember the more the breaker trips the weaker it gets. With Lippert recommending the 80 amp breaker that's good enough for me. I never had mine trip but I didn't want to wait till I started having problems before replacing the breaker. That's what's good about this forum in that there are plenty of members that can forewarn you about problems before you have them yourself. Another example is the toilet. I didn't want to wait till my rv was flooded before changing to the Dometic. As they say 'an ounce of prevention is worth a pound of cure'.

[CADman_KS]

After reading thru this entire thread (GREAT information BTW!), I decided to be proactive on changing out this breaker, BEFORE we had issues. Our breaker had never acted up, but I didn't want to take that chance.

After getting it all done, and reviewing this thread, I realized that ours is wired completely differently than all of the pictures that I saw. It appears that ALL of our power is going thru the cutoff switch in the front. Unfortunately, I can't test that right now, because that main cutoff switch broke, and is stuck in the on position all the time (going in for warranty).

Here is a picture of how mine came from the factory and after changing out the 50A breaker to an 80A. It's hard to see in this photo, but I only have ONE wire coming from battery to the cutoff. The one issue that I see with this, is that the main wire to the cutoff might not be big enough. Other than that, I'm not for sure why it is this way, or if there is any reason to have it the way that most of the others are wired...