Over Current?

[Deuce 10+ year member]

My memphis amp has a warning light that says "over current" and it just came on. Will someone plz help me out with what that means or what i should do to fix it.

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[JimJ 5,000+ posts]

Sounds like you're trying to go under the amp's lowest rated impedance...

 

[revots 10+ year member]

read this, it could also be your ground.

http://www.mikeholt.com/mojonewsarchive/ET-HTML/HTML/Back2BasicsOvercurrentProtection~20020510.htm

 

[Deuce 10+ year member]

i've ran 3 different 1 ohm speakers off of it over the years. It did it once with my old L7 but i didn't think anything about it because it started working again after i turned the amp off for a little while. I just bought a Q 12 D2 and wired it to 1 ohm. It seems to only do it when the sub is beating pretty hard.

 

[revots 10+ year member]

The louder your volume level the more current is pulled. If your ground is insufficient the expelled current has no where to go.

"An overcurrent protection device protects the circuit by opening the device when the current reaches a value that will cause an excessive or dangerous temperature rise in conductors.

Most overcurrent protection devices respond to both, short-circuit or ground-fault current values as well as overload conditions."

 

[Deuce 10+ year member]

ive got 4 gauge ground and 4 gauge power. I thought the ground was supposed to be equal to or bigger than the power. I guess i could find a better place to ground it.

 

[revots 10+ year member]

get a Digital multimeter, choose the OHM selection, put one probe on your amp's ground (make sure it's on metal for a good connection), place the other probe on your ground point. The number should be less than 1, the higher the number the worse the ground.

 

[revots 10+ year member]

It could also be a short in either your ground or power wire. make sure the insulation isn't torn and wire is not exposed along the entirety of the wire.

 

[Deuce 10+ year member]

ok i will. Maybe this will help but like i said it has happened before and i ran my 15 L7 all the time at high volumes and it happened only one time. I turned the amp off on the head unit and then ten minutes later i turned it back on and it worked fine. Hasn't happened since. When i was putting my new box and sub in tonight my ground wire did come out and i put it back in so maybe it really is the ground. Ill go make sure all the connections are solid as well as the wire and check back.

 

[revots 10+ year member]

1,000 watts is thrown around loosley around here so let me see if i can help.

1,000 watts= 1.32 HP, 44,240 ft-lb/min, 56.9 btu/min.

Long story short, upgrade to 2 or 0 gauge wire and the problem will go away. Your amp at high volume is basicaly choking trying to pull current through the cable. Bigger wire equals less resistance (heat).

 

[helotaxi 5,000+ posts]

The overcurrent light signals that the output stage of the amp is attempting to pass more current than it safely can. This is usually an indication of either a load below what the amp is stable to or severe clipping exceeding the duty cycle of the output devices. In no case is it a problem with the ground. A problem with the ground will usually manifest itself as an undervoltage protection warning.

 

[revots 10+ year member]

you're right helotaxi, i read his post about the L7's and assumed it was his ground.

Over voltage Protection – More important in linears, where failure of a pass transistor could easily put excess voltage on IC’s. With switchers, most failures cause no output at all.

 

[Deuce 10+ year member]

I barely have my gain turned up at all from the lowest position (6v). The amp is 1 ohm stable and the sub is wired to 1 ohm. I ran it all day today and the light didn't come on. If it begins to come on frequently i'll address it again. Thanks for the help.

 

[Deuce 10+ year member]

The amp only goes to over current when i play 1 specific song. I just realized that today. Perhaps the song is going so low it makes the ohm load go below 1?

 

[helotaxi 5,000+ posts]

More likely that one song has a recording level higher than whatever you used when you set the gains. As such it overdrives the amp with the current gain setting.