Etec / Perco Switch Electrical Fire

[Robtile]

I don't think this warning is specific to an Etec, but I'd like to share as a heads up and warning. I was installing a Perko battery switch, and a mounting screw (barely) pierced the #2 battery cable insulation. This caused a direct short from the positive side of the battery to the boat. This was impossible to see because the cables are being the switch housing. When I placed the positive battery cable on the #2 battery, the engine wiring insulation caught fire - very quickly - literally within 30 seconds or less.<br /><br />Here's why this happened. First the screw NEVER should have been able to pierce the battery cable. The Perco switch design does not protect the screw from doing this since the plastic is not molded around the screw all the way to the mounting plate. Presumably, when I placed the #2 battery cable on, the power went from the boat, through the transom looking for the path of least resistence to the ground.<br /><br />The negative side of the batteries are commonly grounded to the motor block. So, it appears that the power sought ground through every small ground wire on the engine, melting all the harnesses. Even the small stainless grounding wire from the motor to the motor mount burned away as the power tried to get from the transom to the engine block.<br /><br />Please - be careful. Brand new crestliner 1750 Fishhawk and 90 HP Etec...never been in the water. Thankfully, no one was hurt, nothing seriously burned and I will get away with about $800 in damage. Why the heck the motor isn't isolated from the boat at the mounts with a fused link is a discussion for another forum.....<br /><br />Be careful with those PERKO Switches !!

 

[marinemech1]

Re: Etec / Perco Switch Electrical Fire

your problem could have happened with any motor in essence you provided a dead short to ground

 

[OBJ]

Re: Etec / Perco Switch Electrical Fire

I'm a little reluctant to post here Rob 'cause I've mounted several Perko Battery switches and have never had a problem with one of them. Careful planing is the key to any installation.<br /><br />When you put the cable on the battery post, you should have seen a very large arc. This in itself should have tipped you off of impending trouble......but....since I wasn't there...I'm just guessing....hope thigs work out for ya'.

 

[DJ]

Re: Etec / Perco Switch Electrical Fire

I'm in agreement with OBJ.<br /><br />By the way, ETEC had nothing to do with it.

 

[Robtile]

Re: Etec / Perco Switch Electrical Fire

Agreed about the make/model of the motor, I was careful to note that I didn't "think" the issue was specific to Etec, as I figured grounding placement is similar on all motors.<br /><br />Why no Arc? Maybe because I put the positive terminal on first and actually put the negative on last (rather than the way I described as putting the positive on last)? I might point out that this was the second battery of a two battery system. Battery #1 was connected and well grounded. Is it possible that since that ground on battery #1 was path of least resistence I didn't spark when putting on the negative side of the 2nd battery (the battery whose cable I hit with the mounting screw? I don't know.....<br /><br />I thought also that anyone who might hook up the switch to test it before mounting, and then mount w/o disconnecting the battery ( a definate no no given what happened to me) should think twice. You wouldn't see the arc (if it arced inside the housing) if you compromised the insulation w/ the screw, driving it in with a handheld drill or the like.<br /><br />8501DP is the model of PERKO switch in question, and as you know this is a very common switch. If you look at the bottom screw hole next to where the cable comes in, that's were the screw scraped the wire. Believe me, it wouldn't surprise me if I was the only idiot in the world to nick that wire.<br /><br />Anyway, it's all water under the bridge for me, I just thought I'd share my mistake for the benefit of others. I certainly won't do it again if I live to be 100 <g><br /><br />However, I will hold out that if the switch was molded to protect the screw to the baseplate, it would completely prevent this from happening with no added manufacturing cost.<br /><br />This brings up a question. If I have to charge my two-battery system with a 110 AC/12 DC charger (not the boat alternator), what is the safest way? Should I disconnect all cables and charge each battery individually or can I set the switch to "all" and charge both from one battery connected to the charger without removing the cables?<br /><br />Thanks, <br /><br />Rob

 

[OBJ]

Re: Etec / Perco Switch Electrical Fire

Rob, no one thinks of you as an idiot....we've all made mistakes and have learned from them. Sharing them helps others from making the same mistake. We all thank you for sharing.<br /><br />If it was me, I would turn the battery switch to off and charge one battery at a time if using a single battery charger. If the charger has a monitoring system in it, it may become "confused" and over charge one or the other battery.<br /><br />Thanks again for posting.