Cruisers Forum

  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 11-10-2017, 19:46   #16
Registered User

Join Date: Jul 2016
Location: Traverse City, Michigan
Boat: Hinterhoeller Niagara 35
Posts: 219
Re: Solar ON/OFF switch for 60volt system?

One more thought:

For most cruiser type solar arrays up to 600 watts or so you will be much better off wiring your panels in parallel with the system at ~20 volts.

With larger panel arrays, series configurations and the resulting higher voltages do allow for smaller gauge wiring, with the drawback being the switching and safety problems already discussed.

I would suggest that such systems be designed and installed by qualified solar techs.
Boatwright is offline   Reply With Quote
Old 11-10-2017, 19:49   #17
a64pilot's Avatar

Cruisers Forum Supporter

Join Date: Oct 2013
Location: Jacksonville/ out cruising
Boat: Island Packet 38
Posts: 31,474
Re: Solar ON/OFF switch for 60volt system?

Throw a blanket over the panels, the output will go to zero
a64pilot is offline   Reply With Quote
Old 11-10-2017, 20:02   #18
Registered User
ccannan's Avatar

Join Date: Jun 2003
Boat: Alubat, OVNI 47
Posts: 344
Images: 5
Re: Solar ON/OFF switch for 60volt system?

Originally Posted by ccannan View Post
Use an appropriately rated CB instead of a switch.
ccannan is offline   Reply With Quote
Old 11-10-2017, 20:08   #19
Registered User
Dsanduril's Avatar

Join Date: Aug 2011
Location: Petersburg, AK
Boat: Outremer 50S
Posts: 4,212
Re: Solar ON/OFF switch for 60volt system?

There is a difference between disconnecting an appliance (load) and disconnecting a power supply (solar controller) charging a battery. When you open a disconnect under load there will be a voltage spike. For a load fed from batteries the batteries act as a giant surge arrester. When you disconnect an operating solar controller you're disconnecting from that surge arrester. That means the surge has to be clamped in the controller. And that comes down to controller design. The effect is very similar to disconnecting your alternator under load - the collapsing field can destroy the diodes, but there are designs that can help prevent this.

Inverters are actually prone to failure in the same manner. I've seen a large number of inverter failures that were the result of circuit protection opening on the inverter's load side. If the circuit protection opens it usually means the inverter is at or near capacity, and the resulting surge can destroy the electronics. Again, all comes down to design.

Bottom line, nothing likes being disconnected under load, so if you can remove the load first it is always(?) better. Same reason we generally drop engines down to idle before shifting - sure you can do it at speed, but it's not good for any of the components. With solar that's actually pretty easy - throw a blanket over the panels (even just a section of each panel) or use the 'stop' function built into the controller. Once you've removed the current from an electrical system the voltage really isn't too critical. But proper design calls for a rating that can handle a loaded disconnect because you never know when someone isn't going to operate things properly.
Dsanduril is offline   Reply With Quote
Old 12-10-2017, 17:31   #20
Registered User

Join Date: May 2013
Location: waterford, ny
Boat: hunter 27
Posts: 42
Solar ON/OFF switch for 60volt system?

Go by total wattage or just use a plug as a means of disconnect.
raybobsky is offline   Reply With Quote


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
Why do I have an on/off switch coming off my alternator? theglo Marine Electronics 25 01-02-2017 07:33
float switch far away from pump... should I use the neg side for the float switch? felipe Electrical: Batteries, Generators & Solar 13 02-02-2014 14:20
On Off Switch for Solar Panel greg cook Electrical: Batteries, Generators & Solar 10 02-09-2012 21:15
BlueSea Dual Switch w/ ACR v. 1-2-B Switch Maddog Electrical: Batteries, Generators & Solar 0 13-07-2009 14:56

Advertise Here

All times are GMT -7. The time now is 14:03.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2021, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2021, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.