mini rocker switch

[SailingJerry]

I need a new mini rocker switch as a replacement on my master electric panel. Everything I see online that is rectangular is rated for AC. Or it is round for DC. I need it to be 1/2" by 3/4" inch. Any suggestions?   

[KWKloeber]

No problem using it on DC if it's rated for DC.  The rating should be at least the amperage for the circuit.
Go for it.

kk

I need a new mini rocker switch as a replacement on my master electric panel. Everything I see online that is rectangular is rated for AC. Or it is round for DC. I need it to be 1/2" by 3/4" inch. Any suggestions?

[J_Sail]

No problem using it on DC if it's rated for DC.  The rating should be at least the amperage for the circuit.

I think Ken meant to say, "No problem using it on DC if it's rated for AC." If so, that would be only partly correct.
The rating for a switch is determined both by its current-carrying capacity and its current-interrupting capacity.

When you switch it OFF, as the contacts open an arc forms; with AC this arc vanishes by itself as the AC drops to zero volts briefly each half-cycle. With DC it continues until the gap is wide enough for the arc to extinguish naturally. So, a switch can typically turn OFF higher AC currents than DC, even when the actual current carrying capacity is the same.*

Ken lucks out, though with his statement, because at very low voltages (e.g. <30v) the arc extinguishes so quickly (as the distance between the switch contacts grows beyond a few thousandths of an inch), that the two capacities become similar. Thus at 12 VDC, most switches are rated at the same amperage as they are for 120 VAC.


* for the curious - There's another lesser, but interesting factor having to do with the transfer of vaporized metal from one contact to the other as the switch opens. With AC the transfer is back-and-forth, while with DC it's always in the same direction. Thus the life expectancy for a switch near the upper end of its rating is typically greater with AC than with DC.  In your case, the switch will likely wear out or die from corrosion long before that.

[KWKloeber]

Yep.  Sorry about the typo.  It wasn't worth the effort to explain. LOL. Except that I should have added the caution "not so for the reverse."

kk

[Stu Jackson]

Jerry,  Try this from the Critical Upgrades topic, which you may have read but forgotten some of the important posts:

http://c34.org/bbs/index.php/topic,5078.msg39196.html#msg39196

This is for the old panel switches.  You mentioned mini-rocker, which could be for a newer panel and not for circuit switches, you didn't say.  In the past I'd recommend Radio Shack down the street, but not so much anymore.  Online sources will no doubt crop up in response to your request, I don't have one at my fingertips, but, heck, Defender and West Marine have catalogs online to find stuff like this.

Sometimes when someone asks what time it is, it is not necessary to teach him how to build a clock.

[Dave Spencer]

Jerry,
I had a rocker switch fail on my boat a few years ago.  I replaced it with one in the attached link. As I recall, I found it on Amazon.  It is virtually indistinguishable from the OEM switches.
https://www.carlingtech.com/rocker-switches-611-621-series

[SailingJerry]

No problem using it on DC if it's rated for DC.  The rating should be at least the amperage for the circuit.

I think Ken meant to say, "No problem using it on DC if it's rated for AC." If so, that would be only partly correct.
The rating for a switch is determined both by its current-carrying capacity and its current-interrupting capacity.

When you switch it OFF, as the contacts open an arc forms; with AC this arc vanishes by itself as the AC drops to zero volts briefly each half-cycle. With DC it continues until the gap is wide enough for the arc to extinguish naturally. So, a switch can typically turn OFF higher AC currents than DC, even when the actual current carrying capacity is the same.*

Ken lucks out, though with his statement, because at very low voltages (e.g. <30v) the arc extinguishes so quickly (as the distance between the switch contacts grows beyond a few thousandths of an inch), that the two capacities become similar. Thus at 12 VDC, most switches are rated at the same amperage as they are for 120 VAC.


* for the curious - There's another lesser, but interesting factor having to do with the transfer of vaporized metal from one contact to the other as the switch opens. With AC the transfer is back-and-forth, while with DC it's always in the same direction. Thus the life expectancy for a switch near the upper end of its rating is typically greater with AC than with DC.  In your case, the switch will likely wear out or die from corrosion long before that.

Thanks for this!!! I kept reading about the arcing and was worried about melting/fire. Running 1 - 3 amps is a little safer than a few hundred. Just going to make sure it's US made and not from China. Almost done installing the interior wiring for a new Raymarine e127 display and first time radar.

[J_Sail]

I kept reading about the arcing and was worried about melting/fire. ... Just going to make sure it's US made and not from China.

The arcing is at a nearly microscopic level and is only a concern related to long-term degradation of the contacts. More importantly, at 12v it is a non-existent issue.

CarlingTech is a respected manufacturer. So long as the switch is made by a respected manufacturer and is UL, CSA, and/or VDE approved, don't worry about what country they manufactured it in.

[Gregory M]

I need a new mini rocker switch as a replacement on my master electric panel. Everything I see online that is rectangular is rated for AC. Or it is round for DC. I need it to be 1/2" by 3/4" inch. Any suggestions?   

Just find out in CD, looking for other stuff... Maybe that is what you need.
http://www.catalinadirect.com/index.cfm/product/2380/switch-rocker-34-x-12-mounting-hole-wboot--red-on-indicator.cfm

[Ron Hill]

Guys : What you can always do in a pinch is to take one of the spare (unused/not wired) switches and change it with the inoperative switch until you can get a replacement.
[/b]
Done that a few times while on a cruise.

Guess Ken doesn't read the entire post before making comments 

A thought

[KWKloeber]

Guys : What you can always do in a pinch is to take one of the spare (unused/not wired) switches and change it with the inoperative switch until you can get a replacement.

Don that a few times while on a cruise.

A thought

ahhh ha!  Clever idea.  Ron.
Like stealing one lug nut off of 3 wheels to replace lugs on the 4th wheel that were lost in the Ralphie, "OH, FUDGE!" snow bank?  Been there.

Or, depending on the panel and bird's nest, temporarily move that circuit wire to a spare switch?

[pablosgirl]

Hi Jerry,

I have an 1988 c34 and had the same problem where the mini rocker switches stopped working one by one.  Initially it was the cabin lights switch and as a temporary work around I just moved the cabin wire to an unused switch in the panel.  I replaced all the switches in the panel by calling Dennis Igarashi, a former Seaward employee.  see post for contact info http://c34.org/bbs/index.php/topic,7405.msg58687.html#msg58687.  Also see my post in this thread, it lists the part number you need to order from Dennis http://c34.org/bbs/index.php/topic,8691.msg61733.html#msg61733

I would replace every one of them or at least every one in the bank (six per bank) that has the bad switch.  This is because of the labor involved with replacing one is 95% of replacing all in one bank.  Also, if one has gone bad the others are not far behind in my experience.  The failure does not seam to matter on how much use the switch sees.

Here are some notes on the panel and the procedure that I used to replace the switches.

Notes:
1) All six switches in the right(forward) column of switches are soldered together with a single positive conductor fed from the single push button breaker feeding that bank of switches.

2) The left or aft column of switches is fed from two breakers, so there are two solid conductors soldered to the switches.  One for the top three switches.  And the other soldered to the bottom three switches.

3) the switches are held into the panel with black silicon caulk.  This is also what holds the individual switches together in the column in addition to the solid soldered conductor.  The Seaward also covered the backs of the switches with silicon only leaving the terminals exposed to protect the switches from moisture. 

4) You MUST disconnect and remove the panel from the bulkhead to replace one or all the switches.

Procedure:

0) Disconnect both the AC shore power cables AND the battery banks!!!  Don't want to do any AC/DC arc welding with your body parts!

1) VERY IMPORTANT!!!! You must label each wire that connects to the back of the panel before removal.  there are a lot of wires and many are just black and red.  You cannot rely just on pictures.  You will have three large gauge conductors to the 1-2-B battery switch.  You will have the DC ground buss.  you will have the AC wiring, and you will have all the DC branch circuit wires.  LABEL, LABEL, and LABEL!  This will make the assembly job much easier.

2) find a piece of soft foam at least 1/2" thick to lay the panel face down on.  This will protect the push-button breakers and the finish of the panel.

3) Remove the screw(s) holding the switch common positive conductor(s) to the push-button breakers.

4) Carefully remove the black silicon caulk holding the breaker group into the panel.  I used a x-acto knife to slowly cut away the silicon from the back side of the panel.

5) Remove the solder from the common conductor for the switch(s) that you intend to replace.  If you are replacing all the switches you could fabricate a new conductor to save the removal soldering time.

6) Solder the new switch(s) to the common positive conductor.  Be careful not to over heat the switch!  I ruined one by getting it too hot.  You can use a heat sink between the switch and the solder point to reduce the risk of overheating.  I would test each after soldering it in place.

7) Once the block of switches are together and tested they can be fitted back into the panel.  Fit the block into the panel and apply black silicon around the switch block and between the switches.  I covered the back of the switches like the factory did.

Place the foam used earlier on the chart table top to protect the panel finish and push-button breaker while you re-attach all the wires to the back of the panel.  This is where all those labeled wires make the job faster!

Fair Winds

Paul & Cyndi