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I recently bought some Andersen connectors for connecting high-amp devices to my camping setup in my truck. The idea is they hold together through much rougher conditions than a regular cigarette lighter 12v plug would, as well as being superior in virtually every other way as well.

However they have this notice on them:

Picture of an andersen connector with For Disconnect Use Only written on it

FOR DISCONNECT USE ONLY

I am unclear what that notice actually means. The French above it

NE PAS EMPLOYER POUR LA RUPTURE DU COURANT

Google Translate tells me means

DO NOT USE FOR CURRENT BREAKDOWN

This seems to indicate that the connector should not be unplugged when the system is under load, which makes a lot more sense...

What does this warning signify?

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    \$\begingroup\$ i thnk that it means that it is for infrequent use in an application such as a battery connector, where it is disconnected only when changing batteries .... it is not to be used as a power switch \$\endgroup\$
    – jsotola
    Feb 25, 2020 at 4:09
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    \$\begingroup\$ It looks almost like the English is a bad translation of the French \$\endgroup\$
    – Chris H
    Feb 25, 2020 at 12:06
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    \$\begingroup\$ @Caltor "Do not use as a disconnect device" would be valid, so it's pretty much backwards \$\endgroup\$
    – Chris H
    Feb 25, 2020 at 15:38
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    \$\begingroup\$ @ChrisH: The problem is that the translator failed to see the last two words of the top line, which in this grammatical construct, mean "DO NOT". \$\endgroup\$
    – supercat
    Feb 25, 2020 at 16:00
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    \$\begingroup\$ In short the English translation on the plastic piece is horrible, basically wrong. At the very least, they literally meant to type "disconnected", !!NOT!! "disconnect". Chinese multilingual translation can be as bad as Chinese engineering is good! \$\endgroup\$
    – Fattie
    Feb 25, 2020 at 19:01

7 Answers 7

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The French means 'do not use to break the current'.

In other words, this connector is not to be used as a switch. Only pull them apart when the circuit is drawing no current.

With a 50A rating, and used with DC, breaking the connector circuit is likely to cause an arc as the contacts separate for long enough to damage them.

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    \$\begingroup\$ Search for "Battery isolator switch". They tend to come with a big red key-like handle and are rated for 1000 or 1500A. The intent of that message is that something like this should be Installed upstream of the Anderson connector. \$\endgroup\$
    – user16324
    Feb 25, 2020 at 12:01
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    \$\begingroup\$ @mbrig The official drawings indicate the same warning on the molding andersonpower.com/content/dam/app/ecommerce/product-pdfs/SB50/… \$\endgroup\$
    – DKNguyen
    Feb 25, 2020 at 20:14
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    \$\begingroup\$ @DKNguyen then... what the heck! "Great for battery or other applications where the ability to interrupt circuits is required" is what the datasheet says, including a rating to switching under load. I guess the right hand wasn't talking to the left... \$\endgroup\$
    – mbrig
    Feb 25, 2020 at 20:20
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    \$\begingroup\$ Looking at the datasheet, it might be a difference between the UL and CSA rating. That might also explain why the warning is English/French. So maybe not for disconnecting Canadian batteries, eh? \$\endgroup\$
    – W5VO
    Feb 25, 2020 at 23:29
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    \$\begingroup\$ I think the french means "Do not use as a circuit breaker" -- Meaning it's a plug only, not a line protection device. \$\endgroup\$
    – Chris Cudmore
    Feb 26, 2020 at 17:41
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"For disconnect use only"

should read

"For disconnected use only"

in the sense of

"Only 'use' this socket (i.e., 'put a plug in or out of this socket') when the the power is off."

A good translation would perhaps be

"Do not use this plug as a switch"

or

"Do not use unplugging as a means to turn off."

or what about

"You must turn off the power, before plugging or unplugging this plug."

The basic confusion here:

If you say you are "using" a socket, it usually means that, "today, all day, something is plugged in to the socket". The socket is "in use", it is "full", it is "being used by appliance X".

But the other way to "use" a socket is literally the act of plugging in and plugging out. (As in "use a screwdriver" or "here, use this".)

in this sentence:

"Only 'use' this socket (i.e., 'put a plug in or out of this socket') when the the power is off."

The 'use' means 'the action of putting a plug in or out of this socket'. That's what's going on here! It's somewhat clearer what is meant in French.

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I have worked as an electrician for over 20 years in the U.S. I also hold an associates degree in electrical technology. This is a very common terminology. It means that this only acts as a "disconnect", which means you use this to "disconnect" the power, to either work on the equipment, or as a way to wire in portable equipment. As opposed to a breaker, which means that it is both a disconnect and an over current device, which automatically stops all current from flowing when it pulls too many amps. This is there to stop the wires from overheating in the case of a malfunction. Also from my high school french class I learned that when "ne pas" is used it means "not". As in the statement being expressed is not true

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    \$\begingroup\$ So basically it's telling me that this plug does not contain any fusing or any safety devices? \$\endgroup\$
    – Mark Henderson
    Feb 26, 2020 at 0:25
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    \$\begingroup\$ This seems consistent with the French; la rupture du courant can be translated as "breaking the current," though I don't know if that's truly the idiom for "circuit-breaking" in this field. \$\endgroup\$
    – cjs
    Feb 26, 2020 at 1:19
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    \$\begingroup\$ Yes, absolutely. I assume there is some sort of fusing upstream of this device, in which case you are protected. The french statement does sound weird to me upon further reading, especially considering it has the ce listing. Which seems equivalent to a U.S. ul listing. However, even if it's not necessary to turn off all power draws before unpluging, it would be wise to do so \$\endgroup\$
    – TimmyD
    Feb 26, 2020 at 1:20
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Assuming from the photo that this is an Anderson SB50 connector, it IS rated to be used to disconnect under load. From their data sheet:

UL Rated for Hot Plugging up to 50 Amps Great for battery or other applications where the ability to interrupt circuits is required

So why it say "Only" is the puzzling thing, as in "What CAN'T you do with it?" Most of the time I have found that statements like that which are molded into the housings are just some sort of CYA statement for when something doesn't get used in the intended way, they can say "See? We told you..."

I wouldn't get hung up on it, the data sheet is the definitive authority.

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    \$\begingroup\$ Are we sure that hot plugging also includes hot unplugging, which would be more likely to arc? If that distinction was intended, you'd need a separate switch to interrupt current, but then you could unplug this and then do something else with the rest of the wiring? That sounds weird so probably not. \$\endgroup\$
    – Peter Cordes
    Feb 26, 2020 at 14:44
  • \$\begingroup\$ Valid question, but I interpreted "... where the ability to interrupt circuits is required." to mean the equivalent of unplugging. \$\endgroup\$
    – JRaef
    Feb 26, 2020 at 21:17
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    \$\begingroup\$ @PeterCordes: The data sheets refers to 250 (plug/unplug) cycles at 50A. It probably arcs and damages the plug, but not in a way that it becomes immediately unsafe or unusable. \$\endgroup\$
    – MSalters
    Feb 27, 2020 at 13:33
  • \$\begingroup\$ 250 cycles is not very much, though(!). Which sort of underscores the point ... \$\endgroup\$
    – Will Crawford
    Feb 27, 2020 at 20:55
  • \$\begingroup\$ if being used once per day, you're right. Once per month though, that's over 20 years... \$\endgroup\$
    – JRaef
    Feb 28, 2020 at 0:25
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The wording is entirely correct. The english "Disconnect" is a noun in electrical terms. It is not a verb or the act of disconnecting. It is the means by which the device can be removed from the circuit, such as a battery when it needs replacing. It is the device itself and is to be used only for breaking the connection when the ciruit is not in use. The French have the noun for circuit breaker, which is written, but that is for a device that interrupts a live circuit and the warning is not to use this device in that manner. It makes complete sense to someone who is familiar with electrical connections.

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If you disconnect this plug when the current is, say, 150A and voltage is 50-60V you will see a sort of welding arc, it destroys the connector.

So before disconnection you have to stop the current using some other point of the circuit, not this connector.

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  • \$\begingroup\$ Conceptually you are right, but I suggest you revise your example to limit the current at its rated 50A, possibly using a higher break voltage - both within connector rating. \$\endgroup\$
    – EJE
    May 21, 2022 at 14:53
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This is the reason why they must not be used as connect switches. Lead acid Batteries can surge to > 1000 Amps if very low ESR and mismatched voltages and burn the plating, then oxidize worse.

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Batteries with mismatched voltages can connect with very high surges even greater than the CCA 30 second rating.

After having equalized the surface charge by bridging the batteries with some other breaker, the surge will no longer occur and thus with an Ammeter, you can judge when to disconnect <50A.

It seems two users -2) are making false assumptions in engineering practise to misuse this connector. The French makes perfect sense. If you do not understand it, then you lack the experience to design with it. 50A rating is sufficient for any brain farts.

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    \$\begingroup\$ I fail to relate this answer to the question asked. \$\endgroup\$
    – Christian
    Feb 25, 2020 at 12:07
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    \$\begingroup\$ @Christian I think he's trying to say that, if you're using it to join a battery to an array, there's a possibility that even the voltage mismatch between the battery and the array could be sufficient to drive an arc when making/breaking a loaded connection? Agreed it's not clear. \$\endgroup\$
    – J...
    Feb 25, 2020 at 12:53
  • \$\begingroup\$ @Christian FYI or FWIW \$\endgroup\$
    – Tony Stewart EE75
    Feb 25, 2020 at 14:17
  • \$\begingroup\$ @TonyStewartSunnyskyguyEE75: The instruction should say that it should only be used when the circuit is disconnected via other means, but what the French says is "[top line]DO NOT [next line]USE FOR THE[next line]INTERRUPTION OF CURRENT". Using the device to connect live circuits would also be dangerous, but the instruction relates to disconnection. \$\endgroup\$
    – supercat
    Feb 25, 2020 at 16:03
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    \$\begingroup\$ @supercat true the danger with motor arcs is on disconnect, but intended for auxiliary batteries 🔋 with low ESR it is only for connection that can have this fault current. Therefore the French makes perfect sense for the unspecified yet normal application of an auxiliary battery. This is not intended for a live motor quick disconnect nor would anyone in their right mind do so. \$\endgroup\$
    – Tony Stewart EE75
    Feb 25, 2020 at 17:25

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