You could also disconnect the contactor from the Sevcon and instead, separately turn it on, maybe from your 48v thru an appropriately sized resistor. If the contactor works, then you have a case to be made for the controller contactor control output (or logic) having some issue.
Another thing to check: If the controller validates a remotely sensed voltage before enabling the contactor drive, then you should triple check that the sense wire hasn't flaked out.
Again, these things are pretty dang robust, and it will be a waste of time/money only to find that the HW is all good but that some wire came undone and needs to be corrected in either case.
One last thing: Is it possible that your connections to the contactor coil have been reversed since it last operated correctly? That wouldn't necessarily be a problem, however if you also had external diode suppression on the coil, it could totally explain not getting the contactor to click. As mentioned, the SEVCON contactor control outputs have built-in suppression, so added external suppression (resistor, diode or transorb) should not be needed and might cause the contactor drive to not operate properly (or fail).
Just a thought-
-MT
From: electricboats@groups.io [mailto:electricboats@groups.io] On Behalf Of Larry Brown
Sent: Tuesday, September 15, 2020 9:36 AM
To: electricboats@groups.io
Subject: Re: [electricboats] Motor not powering up
Thanks Myles. I followed the wiring descriptions to get the unit working and have used it about a dozen times running up to 50amps in tests. It ran good if forward and reverse. Nothing in the wiring has changed and my meter reads valid numbers up to the contactor of 53V. This idea that the 24v supply to the coils in the contactor being PWM might not show up on my amp meter seems like it could be leading me astray and that this really is the contactor. I wish I had easy access to one I could use to rule it out but they are something like $120. I'm thinking I'll go ahead and ship both the controller and the contactor and see what TS finds out. I asked if it's possible the config in the sevcon could have been corrupted somehow and rewriting a configuration to it might bring it back. They said they've only seen that happen on two occasions but we'll find out when they get the controller. I'll have to try and get it taken apart and ship it this weekend and hopefully know something soon.
Thanks for your input, everyone. I really appreciate every bit of new information!
Larry
On Tue, Sep 15, 2020 at 12:14 PM Myles Twete <matwete@comcast.net> wrote:
I've used the Sevcon GEN4's including their contactor drive outputs (3 contactor control outputs used in our case). The nice thing is that, properly used, Sevcon's contactor control often includes:
· Built-in transient suppression
· SW-controlled PWM economizing
· Contact-weld prevention (contactor closes only after dV small)
I don't have vast experience with these, but I know the design is robust. I also know that Sevcon has great latitude to modify the internal configuration, timing and functionality of the Gen4 units (ours were actually Gen4 motor controllers repurposed as DC to DC converters). There are lots of safety features, fault indicators and such---and I'm sure the contactor drive outputs are quite protected. I didn't hear of a single case of a contactor drive output failure. I personally had Sevcon tailor one contactor drive output for our needs (PWM-drive a 24v coil from 48vDC rail plus PWM economizing).
Before sending your controller back to TS, I would double check your wiring against the recommended wiring configuration. Having said that, hardware fails and software gets configured wrong. Sometimes the wrong hardware/software configuration gets shipped. You can have several identical looking GEN4 units all with different configurations and even voltage ratings. The markings on the controller S/N plate are important and should be checked against what it should be.
Best of luck-
-Myles Twete
From: electricboats@groups.io [mailto:electricboats@groups.io] On Behalf Of Lars Jensen
Sent: Tuesday, September 15, 2020 4:50 AM
To: electricboats@groups.io
Subject: Re: [electricboats] Motor not powering up
The line-contactor power from the sevcon is pwm, i.e. it is a pulsed 20-24v, which then should trigger the relay and provide the 48v main power - with a loudably click . The pwm is difficult to measure with a voltmeter. And the sevcon measures if power is provided on the 48v even if there is no 24v on the line-contactor - and goes into an error called "fused main contactor" (or similar)
Lars
Den tir. 15. sep. 2020 kl. 13.33 skrev Larry Brown <elcapitanbrown@gmail.com>:
So my understanding is that the switch going into the sevcon allows the sevcon to determine that the user has switched it on. It goes through some logic to determine if it's ready to engage the contactor. So it runs between 20 and 24 volts to the small poles on the contactor. This engages the contactor and supplies the full 48v to the Sevcon. So if there is no voltage on those small posts the Sevcon is not turning the thing on. I was thinking those poles were from the switch but in fact they are not. (which makes sense) The odd thing here is that the Sevcon has a green light so it doesn't think anything is wrong. I'm really just trying to understand this as I go. I am certainly no expert, but what he was saying makes sense to me so far...
On Mon, Sep 14, 2020 at 11:16 PM <jack21322@gmail.com> wrote:
if the contactor poles are not working shouldn't you change that before dismantling the sevcon?
On Mon, Sep 14, 2020 at 2:23 PM Larry Brown <elcapitanbrown@gmail.com> wrote:
So I got a hold of TS today. They said the small poles on the contactor should show 20 to 24v when it's energized to make the contactors close. Probing those posts I get no voltage. They had me probe the wires through the harness and they show continuity. So they are asking that I send them the controller so they can put it on a bench. So off I go to dismantle things.
I really hope I'm missing something and it's fine. I don't see how, but that would be the best outcome. I held on to this unit in my home for a couple years until I had the opportunity to do the install. After getting it installed I've taken the boat off the dock 1 time. I've run it about a dozen times at the dock so on average I got about $80/hr use out of it. Sevcon sounds like they are a pretty good outfit but this is very disappointing. If it is the controller they will make a case for getting a replacement unit from sevcon but no guarantees since it's 3 years old. I'll keep you guys posted.
On Mon, Sep 14, 2020 at 11:46 AM Bob Jennings <heatnh@gmail.com> wrote:
Larry, won't be at my boat till next week.
Matthew brought up a good point. If you can't hear the contactor clicking/pulling in when you turn the key, it's busted.
The contactor on my boat is a Tyco. Should be able to find a replacement easy enough.
On Mon, Sep 14, 2020, 11:35 AM <jack21322@gmail.com> wrote:
Just so you know, I have the 48v thunderstruck kit and have had the same contactor problem- proper voltage on one pole and significantly reduced voltage on the other. Ended up replacing the contactor and she worked fine. My connections on the contactor were kinda loose when I went to diagnose it at first with the multi meter, but seems yours were tight.
I think the contactor they provide with the kit could be low quality now that I read you are having the same problem. If you end up replacing it with a different kind let me know because I'm thinking of getting a spare contactor the keep on board in case it happens again underway or in a foreign country.
Best,
-Jack
On Sun, Sep 13, 2020 at 11:51 AM Larry Brown <elcapitanbrown@gmail.com> wrote:
Reading up it seems I could leave the throttle in (off position) run a screwdriver across the Line and Terminal contacts and should see the clearview showing the correct voltage to confirm the contactor is not fully engaged? I'm unsure as to why it isn't simply 53V or 0V on the Terminal side to the controller. Seems it would act like a physical switch and either be on or off... But bridging the two with no load seems like it shouldn't hurt.
Larry
On Sun, Sep 13, 2020 at 2:13 PM Larry Brown via groups.io <elcapitanbrown=gmail.com@groups.io> wrote:
I went down to the boat yesterday to clean the bottom and figured I'd run the motor a little to keep that warm and fuzzy feeling that I'm ready to go when I need to and no warmth or fuzz to be had. Turning the key on to activate the Sevcon caused the sevcon green light to illuminate and the Clearview screen to come on. However, the clearview shows 00 for voltage. My battery monitor clearly shows the voltage at 54V (48V system). When I check the lead going into the contactor to ground I get 53V but on the lead coming out of the contactor going to the controller I'm readying approximate 10V. I suspect this is the culprit? Or is there a reason the lead between the contactor and the controller would read low?
Looking at the contactor it looks like it's a sealed/waterproof unit (From the Thunderstruck kit, or at least water resistent). All wires nuts are tight on their wire leads from both incoming wire from the battery bank and outgoing wire to the controller and the two that run to the key switch. It's in a dry spot and I've run the motor maybe a dozen times in the 2 years I've had the equipment. (my project was on hold). There is no apparent corrosion externally whatsoever so I'm not sure what could have caused it to fail. We are not far away from the lightning capital of the country (Lakeland Fla) but I don't see any charred marks on anything, the solar charge controller is working fine. Are contactors flaky parts or parts that I should always have a spare available for? I really thought having such a simple system that's relatively new that was working as advertised would be doing so for quite a while. Glad I found out at the dock when I didn't need to move the vessel :-P
Thanks in advance for anything you guys can offer as advice.
Larry
--
Larry Brown
S/V Trident
Palm Harbor, FL
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Larry Brown
S/V Trident
Palm Harbor, FL
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--
Larry Brown
S/V Trident
Palm Harbor, FL
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--
Larry Brown
S/V Trident
Palm Harbor, FL
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--
Larry Brown
S/V Trident
Palm Harbor, FL
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