We have a Trace inverter with battery charger model #U2512SB. It is feeding back power to the slip pedistal. When battery charger is turned off, all is good. The inverter had a relay switch that when power cord is unplugged the inverter comes on. When the feedback reading from the power cord pedistal end was done it was plugged into the boat! Could this be caused by the battery charger? Or possibly a bad relay switch.? I do know one thing, this is a dangerous situation. Not sure how long this has been going on, it was found by accident by maintenance crew who noticed our pedistal box was hot.
50 amps coming OUT of pedistal end of power cord when power cord is plugged into boat
- Thread starter Turner
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tiltrider1
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I believe you have a Trace SW2512. This is one of the best units ever made. In fact I wouldn’t mind buying it off of you even though it’s probably close to 20 years old. There is nothing wrong with the unit. It is programmed wrong for your use. Some how it has gotten programmed to feed power back to the grid. There is a hidden menu. You push both the red and the green button at the same time while in the menus mode. This will put you in the advanced menu were you can turn off this feature. You might be better off to pay a tec to come out and train you on this unit rather than attempting it your self. You should go on line and down load the manual if you don’t already have a copy. You will see that it is a very complex unit that does more things than you ever imagined.
Thank you, you made a lot of sense. We are definitely getting an electrician to come adjust it. Glad to hear nothing wrong with the unit.
We put a meter on the incoming shore power recepticle on the side of the boat while the inverter was on.
Lou_tribal
Guru
That was a typo, 49 volts was reading on the boat incoming shore power recepticle, in other words it was back feeding when not plugged into the pedistal. Plug into pedistal, inverter automatically cuts off.
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I agree 100%
Those older Trace inverters are rugged. They have a huge surge capacity to start motors and compressors. I had one for over 20 years without any problems. Would still have it if it was pure sine wave.
Follow tiltriders direction and you will be back in business.
[emoji106]
twistedtree
Guru
You said the model is a U2512SB, which is a valid model number, so no reason to assume it's actually an SW model. They are quite different, with the U being a modified sine wave inverter, not a full sine wave like the SW. Still a good inverter nonetheless.
If you read voltage on the boat's inlet with the power cord not connected to anything, AND the inverter shuts down when you do connect shore power, then I agree there is a fault in the inverter. Perhaps a fused relay.
But diagnose it carefully since it's not uncommon to measure small voltages on devices that are actually turned off, especially older gear. If the voltage persists with a load on it, then there is a problem.
But heck, if you ran that inverter until now, it owes you nothing. Celebrate, and replace it.
If you read voltage on the boat's inlet with the power cord not connected to anything, AND the inverter shuts down when you do connect shore power, then I agree there is a fault in the inverter. Perhaps a fused relay.
But diagnose it carefully since it's not uncommon to measure small voltages on devices that are actually turned off, especially older gear. If the voltage persists with a load on it, then there is a problem.
But heck, if you ran that inverter until now, it owes you nothing. Celebrate, and replace it.
Ski in NC
Technical Guru
49v is not 110v, so there may be no amps behind it. If no amps (really mA) it might not be a safety problem. Just a residual from capacitance, whatever. Put a resistor across it and see what happens to the voltage. Might go to zero.
High Wire
Guru
ok. That is a whole different situation. There should be 0 volts. Im with Ski and try putting a pig-tailed 40 watt 120v old school light bulb across the shore power cord terminals. If there is enough to make the bulb glow, then more than enough to kill.
gsholz
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What you are seeing is "induced" voltage, aka "ghost" voltage. A wire carrying current will induce (magnetically couple) a voltage in nearby wires. There will be very little energy behind it but you can "measure" it with a high-impedance voltmeter. What you need is a low impedance mode (low-Z) on your multimeter. Multimeters targeted at electricians typically have that mode as this is a common problem for them. There is nothing wrong with your shore power setup.
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This inverter has been on this boat from the beginning, 1984. It works perfectly and so does the battery charger, after looking at the diagram, I believe it has a built in relay,. And the way it works , I think, when you plug or power the shore power in the relay shuts the inverter off. So, there is no feed back to pedistal, but if you unplug or shut power off the relay turns inverter on. Now that when voltage is at shore plug receptacle at boat. I turly believe it's been this way from the time of installation. This is to dangerous . I'm not going to play technician, I'm going to hire a professional. Thank you
twistedtree
Guru
Getting help is the right thing to do if you are at all uncomfortable working on it yourself.
The U2512SB is an Inverter/Charger. Your understanding of the relay operation is pretty good. With no shore power (or gen, if so equipped), it inverts and powers loads, and the incoming AC feed is disconnected. When shore power is present, the U2512SB detects that and operates the relay, connecting all the loads directly to shore power. It also puts the inverter into charger mode, and starts to charge your batteries. When incoming AC goes away, it again disconnects, the charger stops, and the inverter resumes powering the loads. This operation is typical of most all inverter/chargers.
Unless the unit is generating a fault when you apply shore power, I suspect there is absolutely nothing wrong, and the tech who thought the pedestal was warm because of your inverter didn't really know what they were talking about. The measured voltage on the shore power inlet to the boat is just a zero current, induced voltage as described by someone earlier, and is probably harmless. But absolutely worth verifying.
I agree with you a 100%. I m on the boat now and traveled 4hr using the inverter as usual,. But to be safe I made sure the shore power recepticle on boat was caped,. I truly believe it is working as should,. Thank you
I'm curious, how did you discover this, what made you check?
If you are calling in a tech, make sure he or she is ABYC Electrical Certified, that way you'll know they know what they are doing and not waste their time and your money, especially for something like this.
You can search for techs here https://abycinc.org/mpage/findatech
(In China, bound for Malaysia yard)
The marina tech found it by chance. He was checking each pedistal and noticed ours was hot to touch and unplugged us. Since that time we have found a list if things that need correcting such as no switch between shore power and inverter, inverter is not grounded ( this is suspected to be where the main problem is that is causing the feed back to shore power pedistal). I'm adding a galvanic isolator on ground wire shore power plug, also replacing the shore power cord. After hours of reading these are what we have found. On the Mississippi Gulf Coast there is ONE certified marine electrician! We are on his waiting list about 3 months away. I will be correcting the issues we have found and when we come up on his list he will do a complete inspection of all the electrical. Until these changes are made inverter will not be used and will be turned off.
DrissZougari
Senior Member
Most Smart Chargers will act this exact way by sensing voltage. I believe that your boat is connect correctly by switching to charging the batteries mode when power is available at the dock (plugged) and to switch to inverter mode when you are disconnected from the dock. this is not a dangerous situation since most people will turn off the power at the dock first then disconnect the boat side first.
The dangerous situation was that the inverter had a 50 amp feed back coming out of the pedistal end of the shore power cord, enough to kill or seriously injure someone. The inverter wires were a tangled bird's nest with splices through out with various color wires being sliced into existing wires, no way to tell by looking if a wire was hot, neutral or ground. Having realized the extent and complexity of the numerous issues we completely disconnected the inverter, have ordered a AC panel box and breakers to completely separate the AC from the DC system. The AC system has been relocated and wired correctly and coherently. We will get on the 3 month waiting list for the marine electrician and have him come and connect the inverter correctly. Having made these changes we feel certain that the electrical system is completely safe and will not electrocute anyone on board or anyone swimming in the proximity of the boat.
