Cruisers Forum
 


Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on Cruisers Forums. Advertise Here
 
Thread Tools Search this Thread Rate Thread Display Modes
Old 23-02-2020, 01:54   #1
Registered User
 
the dude abides's Avatar

Join Date: Sep 2016
Boat: Slocum 43
Posts: 106
Victron 3600 isolation transformer output drop

My isolation transformer (step down from 230 - 110) is showing 230 voltage input from the shore power and only 35 voltage output. It has been successfully working for years. I was running the AC, 2 days before it tripped, didn't trip the RCD but it tripped the 16 amp fuse on the front of the transformer. 2 days later it happened again, I pushed the 16 amp fuse button in and am now only getting 35 volts. Anyone out there have any idea on what is happening? Cheers
the dude abides is offline   Reply With Quote
Old 23-02-2020, 03:21   #2
Registered User

Join Date: Sep 2012
Posts: 36
Re: Victron 3600 isolation transformer output drop

Sounds like it could be a short-circuit in something that works intermittently, like the Air cond. If you turn everything off (including the battery charger) do you get 110V? If you do, the Victron is probably OK, but something is shorted. The safe thing to do would be to call a marine electrician. If that is not feasible, you could turn devices back on one at a time and observe. Leave the air cond. units for last, turn them on with the thermostat down to the min temp and wait for the compressor to turn on before moving to the next one. This procedure is dangerous, though, as the short-circuit can start a fire. Have a CO2 or Halon-type fire extinguisher handy. The 16 amp fuse saved you the last two times, but there is no guarantee that it will do so again. Good luck!
southatlantic is offline   Reply With Quote
Old 23-02-2020, 04:22   #3
Registered User
 
the dude abides's Avatar

Join Date: Sep 2016
Boat: Slocum 43
Posts: 106
Re: Victron 3600 isolation transformer output drop

thanks for your reply. So I have 2 switchboards. the switch board that is kaput is the one that only gets used on shore power. There is a power on switch there for this board, and under that is AC, some outlets, water heater. There is only 35 volts going to the power board when I switch it on. I switch the power off, on the switch board I get nothing. so I have 230 going in and only 35 coming out, but here is where is gets tricky, I put the multi reader in the saloon power points, it reads 110. The shore power is wired directly into this transformer. Its melting my brain. Cheers
the dude abides is offline   Reply With Quote
Old 23-02-2020, 05:13   #4
always in motion is the future
 
s/v Jedi's Avatar

Cruisers Forum Supporter

Join Date: Feb 2009
Location: in paradise
Boat: Sundeer 64
Posts: 18,866
Re: Victron 3600 isolation transformer output drop

I recommend you email “ support at victron dot nl “ which is their main office in the Netherlands. Do not forget to mention the breakers on the front.

I am pretty sure they will tell you there is a problem with those breakers. New transformers don’t have them anymore. The good news is that they can be replaced with jumpers made simply with crimp connectors.

I don’t want to tell you to go ahead with that because I am not Victron and I don’t know your knowledge level on the subject. But if you have a double pole breaker in front of the transformer, you should be good to do the patch with that breaker off (use multimeter to confirm it’s safe), then disconnect the fuses and use the multimeter to test them for continuity. You should find the problem. Then put the jumpers in and while keeping your hand on the breaker, turn it on.

So you should not do the above; it’s just how I would restore power aboard
s/v Jedi is offline   Reply With Quote
Old 23-02-2020, 05:27   #5
Registered User
 
the dude abides's Avatar

Join Date: Sep 2016
Boat: Slocum 43
Posts: 106
Re: Victron 3600 isolation transformer output drop

The shore power goes directly to the transformer at the input at 235, the output side of the transformer is at 35, then from the output is goes into an RCD, when it tripped the RCD did not, but the transformer did. This is why it has me beat. To those breakers are also 35 on the switch board that is only activated with shore power. I am kind of worried that it is the transformer.
Thanks for the reply Jedi. Sailed through Indo last year with a boat called Kenobi by the way. I am in Langkawi at the moment. Hard to get expertise for this here
the dude abides is offline   Reply With Quote
Old 23-02-2020, 05:29   #6
Registered User
 
the dude abides's Avatar

Join Date: Sep 2016
Boat: Slocum 43
Posts: 106
Re: Victron 3600 isolation transformer output drop

I did write to Victron message board about this as well. Thought I would give it a go here as well. Waiting for a reply. Much appreciated - cheers
the dude abides is offline   Reply With Quote
Old 23-02-2020, 05:41   #7
always in motion is the future
 
s/v Jedi's Avatar

Cruisers Forum Supporter

Join Date: Feb 2009
Location: in paradise
Boat: Sundeer 64
Posts: 18,866
Re: Victron 3600 isolation transformer output drop

Quote:
Originally Posted by the dude abides View Post
The shore power goes directly to the transformer at the input at 235, the output side of the transformer is at 35, then from the output is goes into an RCD, when it tripped the RCD did not, but the transformer did. This is why it has me beat. To those breakers are also 35 on the switch board that is only activated with shore power. I am kind of worried that it is the transformer.
Thanks for the reply Jedi. Sailed through Indo last year with a boat called Kenobi by the way. I am in Langkawi at the moment. Hard to get expertise for this here
Okay, you need to rewire that. The RCD must be between shore power inlet and the transformer.

The transformer will be okay, it is a high quality ring core unit. When it would short, you will have lots of smoke from the wire insulation.

In your shoes, I would take the output cable off the unit, then move the RCD to the input side, then with everything off and safe remove the two fuses (easy, just pull them off the blade connectors on the pcb) and measure them. You will find that they have high resistance. They are thermal safeties, not regular breakers and they are flawed.

Then with the output still disconnected, put two jumpers on the pcb connectors in place of the fuses, connect shore power cable, then flip the rcd to ON while being ready to flip it back off. I bet you hear the relays clicking and it’ll come on-line. If so, measure output terminals, make all safe again and reconnect output.

(again, not telling you to do that, it’s just what I did to fix mine) I must add that I am a licensed electrician so I’m familiar with this kind of work while most cruisers are not and it may not be advisable that they do it themselves
s/v Jedi is offline   Reply With Quote
Old 23-02-2020, 05:48   #8
Registered User
 
the dude abides's Avatar

Join Date: Sep 2016
Boat: Slocum 43
Posts: 106
Re: Victron 3600 isolation transformer output drop

this is what my manual says:

A Residual Current Device (RCD) or Ground Fault Circuit Interrupter (GFCI)
must be installed in the output cable of the isolation transformer. For this RCD
to operate correctly, the output neutral must be connected to ground (= all the
metal parts in the boat). This is achieved by placing a jumper on male pushon connectors J21, J33 (see fig 5), and by grounding the enclosure of the
isolation transformer.
the dude abides is offline   Reply With Quote
Old 23-02-2020, 06:01   #9
always in motion is the future
 
s/v Jedi's Avatar

Cruisers Forum Supporter

Join Date: Feb 2009
Location: in paradise
Boat: Sundeer 64
Posts: 18,866
Re: Victron 3600 isolation transformer output drop

Quote:
Originally Posted by the dude abides View Post
this is what my manual says:

A Residual Current Device (RCD) or Ground Fault Circuit Interrupter (GFCI)
must be installed in the output cable of the isolation transformer. For this RCD
to operate correctly, the output neutral must be connected to ground (= all the
metal parts in the boat). This is achieved by placing a jumper on male pushon connectors J21, J33 (see fig 5), and by grounding the enclosure of the
isolation transformer.
I am assuming your boat is wired for US standards? If so then those instructions are good. But you still need another one on the input side. The one on the input side is the one protecting the boat from whatever they messed up ashore... the one on the transformer output is for adapting to the wiring system you have aboard. The output of the transformer is a completely new power source, galvanically isolated from shore power. As your boat expects a grounded neutral, you need to do that on the output side of the transformer. Where does it go from the rcd? To your main panel, or is the rcd in the main panel itself?

The rcd I meant in that needs to be right after the shore power inlet is a separate one. I even believe ABYC recommends that it must be within a foot or two from the inlet. It also allows you to quickly switch shore power off as well as protect the transformer.

Edit: on older boats it’s just a double pole breaker right after the inlet.
s/v Jedi is offline   Reply With Quote
Old 23-02-2020, 06:08   #10
Registered User
 
the dude abides's Avatar

Join Date: Sep 2016
Boat: Slocum 43
Posts: 106
Re: Victron 3600 isolation transformer output drop

yes it is wired for US standards. transformer steps down, actually goes into a junction box then into the transformer, so it splits there so I can actually use 110 and 230.

From the RCD is goes directly to the switch board. The transformer and RCD is in my lazerette.
the dude abides is offline   Reply With Quote
Old 23-02-2020, 06:14   #11
Registered User
 
the dude abides's Avatar

Join Date: Sep 2016
Boat: Slocum 43
Posts: 106
Re: Victron 3600 isolation transformer output drop

something which has just clicked in my head, connection and busbar. Could that have an impact?
the dude abides is offline   Reply With Quote
Old 23-02-2020, 06:27   #12
always in motion is the future
 
s/v Jedi's Avatar

Cruisers Forum Supporter

Join Date: Feb 2009
Location: in paradise
Boat: Sundeer 64
Posts: 18,866
Re: Victron 3600 isolation transformer output drop

Quote:
Originally Posted by the dude abides View Post
yes it is wired for US standards. transformer steps down, actually goes into a junction box then into the transformer, so it splits there so I can actually use 110 and 230.

From the RCD is goes directly to the switch board. The transformer and RCD is in my lazerette.
Okay. The double pole breaker/rcd should go between shore power inlet and the junction box.

For now you can just remove the shore power cable from the inlet for testing. When you put it back in with the jumpers installed, make sure you can hear if the relays are clicking instead of “bad” sounds.

I will comment below about what to do when your transformer is up again.
s/v Jedi is offline   Reply With Quote
Old 23-02-2020, 06:30   #13
Registered User
 
the dude abides's Avatar

Join Date: Sep 2016
Boat: Slocum 43
Posts: 106
Re: Victron 3600 isolation transformer output drop

shall do. Thank you for your time and answering, much appreciated Jedi
the dude abides is offline   Reply With Quote
Old 23-02-2020, 06:40   #14
always in motion is the future
 
s/v Jedi's Avatar

Cruisers Forum Supporter

Join Date: Feb 2009
Location: in paradise
Boat: Sundeer 64
Posts: 18,866
Re: Victron 3600 isolation transformer output drop

This schematic has more than you need, but it shows the correct path of shore power inlet, breaker, transformer, breaker, main panel.

The breaker between shore power inlet and transformer must be 30A because it must allow you to hook up to 120V when 240V is not available.

You need to remove the 240V feed from junction box to panel. Everything should be behind the isolation transformer, even the smallest bypass can not be tolerated. It puts your boat at risk and your personal safety as well.

My schematic shows how to do a 120/240V service the right way. The output of the transformer is set at 240V and the inverters/chargers are 240V as well. Then where you want 120V service, you install an auto transformer which creates a new neutral.

You can also install the auto transformer directly behind your isolation transformer and use your 120V inverters/chargers.

Key is that shore power goes into the isolation transformer only. Also, check that you do not have the ground jumper installed (Victron manual explains it is needed when hauled out). There should be no connection between shore power ground and the ground lead at the isolation transformer output. Right now I fear that you have that because of the diversion around the transformer from the junction box. This exposes all underwater metals to galvanic corrosion
Attached Thumbnails
Click image for larger version

Name:	F5C11193-6D68-4B3E-B825-B353D262CDC6.jpg
Views:	429
Size:	161.1 KB
ID:	209281  
s/v Jedi is offline   Reply With Quote
Old 23-02-2020, 12:27   #15
Registered User

Join Date: Jun 2013
Location: canada
Posts: 4,642
Re: Victron 3600 isolation transformer output drop

if you are getting 230v at it's input and 35v and it's output, with no load (ac panel off), it's ****ed. who cares what breakers you have where. that has nothing to do with it. moving a breaker from after to before is not going to change the readings directly at the box.
smac999 is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Heads Up - Victron Isolation Transformer s/v Jedi Electrical: Batteries, Generators & Solar 115 04-06-2023 06:46
Isolation Transformer: Victron vs Mastervolt vs Charles wilsodf Electrical: Batteries, Generators & Solar 87 07-07-2016 12:33
For Sale: Victron 7 KW 230/240 vAC Isolation Transformer - $500 rkupsaw Classifieds Archive 0 23-03-2011 10:06
Victron Isolation Transformer Voltage Increase Ultimarv Electrical: Batteries, Generators & Solar 5 06-09-2010 09:42
Isolation transformer Pa La O La Construction, Maintenance & Refit 11 12-08-2008 13:14

Advertise Here


All times are GMT -7. The time now is 21:41.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2024, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.