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Post by mundocane on Jul 30, 2021 20:42:17 GMT -5
I need a bit of advice. Purchased amp 11/1/13. Enjoy the amps clarity and breadth. Sent in to Emotiva for repair in Feb, 21. The amp was dropping in to protect - front LEDs flashing red, worked if reset. While gone for repair powered system with two Rotel amps with no issues. Got the amp back, Emotiva could not find a problem. Amp is now dropping in to protect just plugged in with nothing wired to it - simply plugged in, powered on and drops in to protect. There is no predictability to when this will happen.
Anyone had this experience? Thanks
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Post by ttocs on Jul 30, 2021 21:26:44 GMT -5
Is amp plugged directly into power outlet?
Are you handy with a multi-meter? If so, measure AC voltage between Neutral (the larger slot of an outlet) and Ground, then between the Hot (the smaller slot) and Ground. You would think that Ground/Hot would measure 120V (USA) and Neutral/Ground (N-G) would be 0V, but you'd be wrong unless your outlet is perfectly balanced. Usually there is some voltage on the Neutral, but it's very low to extremely low AC voltage. There's a spec for how much is acceptable which I don't recall exactly what the high range is, but I know 5% is acceptable, but it may be higher. So if we use 5% of 120V, then the N-G voltage can be 6V without causing problems.
When the electrical panel in the home is Load Balanced correctly, the loads are arranged in such a way that the power is distributed fairly evenly on each Hot leg. Sometimes the circuits can be arranged such that there is a load imbalance which throws more voltage on the neutral and when this gets too high, things can malfunction.
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Post by mundocane on Aug 1, 2021 16:47:30 GMT -5
I really appreciate you taking your time to respond to my query. Checked the circuit and there is, indeed, a voltage issue. The entire house is nicely balanced with the exception of the one used by the amp. It does not appear to be the neutral but a bad ground. Will need to trouble shoot to locate the issue. Unfortunately, will have to wait till end of August as I broke my left hand mountain biking and working with electricity requires manual dexterity. Will follow up to close the loop once I can work on it.
Cheers - Mundo
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Post by ttocs on Aug 1, 2021 17:19:41 GMT -5
Good goin'! Glad you found the issue.
Hope that hand mends well!
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Post by leonski on Aug 2, 2021 0:40:53 GMT -5
I really appreciate you taking your time to respond to my query. Checked the circuit and there is, indeed, a voltage issue. The entire house is nicely balanced with the exception of the one used by the amp. It does not appear to be the neutral but a bad ground. Will need to trouble shoot to locate the issue. Unfortunately, will have to wait till end of August as I broke my left hand mountain biking and working with electricity requires manual dexterity. Will follow up to close the loop once I can work on it. Cheers - Mundo One of those 'outlet checkers' for 6 or 7$ requires no manual dexterity. Man, is mountain biking potentially dangerous. A buddy of mine once cracked some ribs. |
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Post by ttocs on Aug 2, 2021 12:56:54 GMT -5
I really appreciate you taking your time to respond to my query.  Checked the circuit and there is, indeed, a voltage issue. The entire house is nicely balanced with the exception of the one used by the amp. It does not appear to be the neutral but a bad ground. Will need to trouble shoot to locate the issue. Unfortunately, will have to wait till end of August as I broke my left hand mountain biking and working with electricity requires manual dexterity. Will follow up to close the loop once I can work on it. Cheers - Mundo The only time I’ve come across voltage on the ground was when a newly built horse barn (they used their own sub electrician, not one of ours) had a Neutral connection come loose. |
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Post by AudioHTIT on Aug 2, 2021 16:09:17 GMT -5
I really appreciate you taking your time to respond to my query.  Checked the circuit and there is, indeed, a voltage issue. The entire house is nicely balanced with the exception of the one used by the amp. It does not appear to be the neutral but a bad ground. Will need to trouble shoot to locate the issue. Unfortunately, will have to wait till end of August as I broke my left hand mountain biking and working with electricity requires manual dexterity. Will follow up to close the loop once I can work on it. Cheers - Mundo The only time I’ve come across voltage on the ground was when a newly built horse barn (they used their own sub electrician, not one of ours) had a Neutral connection come loose. When we built our house, my wife and I were the electrical subs (and general, and finish carpenter, and fix the s#!t other subs mess up). When everything was done and we’d passed final I started getting some odd measurements and started troubleshooting back to the main panel. Eventually I determined it was the feed (the left side I’m not supposed to mess with). I called PG&E who sent a guy out, they found a loose lug on one of the 400A service lines that cause it to intermittently go under voltage. Fortunately I caught it before any of our motored devices (well, tank, fridge, etc) went bad. I’d forgotten about the balancing, but it did come up again when we moved some sub-panels around. Good call! |
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Post by housetech on Aug 2, 2021 16:59:19 GMT -5
Voltage between the neutral & ground is not uncommon. Ideally it should be 0 volts but in the real world 0.5 volt is not unusual. When it gets to 2.0-2.5 volts IT'S A PROBLEM for digital electronics.
Various reasons why- poor grounds between main panel & subpanel, undersize wire gauge, poor/corroded connections, too many branches off one circuit, bad wall socket, Tying neutral & ground together before they terminal in the panel and more.
I was the product advocate for a new product and we were going through P.S. & circuit bds way beyond normal, all across the country. I discover the problem: neutral to ground voltage exceeding 2.0 volts. Years ago, trying to explain electronics to an electricians was difficult. National Electrical Code adopted new rules to eliminated the problem of grounds vs neutral.
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Post by leonski on Aug 2, 2021 18:01:48 GMT -5
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Post by DavidR on Aug 2, 2021 18:36:38 GMT -5
OK,read the posts and housetech got me curious. I grabbed my Fluke and went to the easiest to reach, the master bath that's a GFI outlet and it had a window fan plugged in and running. Its one of those with the AC motor that I call transformer motors as the plates resemble an old style transformer. I had 0.417 VAC. I started going around the house and every one I checked had a different reading. They ranged from 0.417 to 0.003 VAC. Normal? |
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Post by ttocs on Aug 2, 2021 18:51:37 GMT -5
OK,read the posts and housetech got me curious. I grabbed my Fluke and went to the easiest to reach, the master bath that's a GFI outlet and it had a window fan plugged in and running. Its one of those with the AC motor that I call transformer motors as the plates resemble an old style transformer. I had 0.417 VAC. I started going around the house and everyone I checked had a different reading. They ranged from 0.417 to 0.003 VAC. Normal? Yes. 3% of normal voltage in the USA is allowable. When we had the issue at a customer house there was 47V on the Ground so I called the barn builder to have his electrician come out to fix. In the meantime I had my electrician find the cause so I'd know what was going on. He was able to find the loose connection but we had to leave it that way until the other electrician came so he could then check everything. Luckily, being a barn, there aren't very many circuits for outlets. The problem was only discovered the first time another worker plugged a power tool into an outside outlet and it wouldn't work, but the circuit wasn't tripped. So I put my meter on it and was shocked (the expression "shocked", not electrically speaking) and perplexed. But my electrician knew what to look for. |
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Post by DavidR on Aug 2, 2021 18:59:50 GMT -5
OK,read the posts and housetech got me curious. I grabbed my Fluke and went to the easiest to reach, the master bath that's a GFI outlet and it had a window fan plugged in and running. Its one of those with the AC motor that I call transformer motors as the plates resemble an old style transformer. I had 0.417 VAC. I started going around the house and everyone I checked had a different reading. They ranged from 0.417 to 0.003 VAC. Normal? Yes. 3% of normal voltage in the USA is allowable. When we had the issue at a customer house there was 47V on the Ground so I called the barn builder to have his electrician come out to fix. In the meantime I had my electrician find the cause so I'd know what was going on. He was able to find the loose connection but we had to leave it that way until the other electrician came so he could then check everything. Luckily, being a barn, there aren't very many circuits for outlets. The problem was only discovered the first time another worker plugged a power tool into an outside outlet and it wouldn't work, but the circuit wasn't tripped. So I put my meter on it and was shocked (the expression "shocked", not electrically speaking) and perplexed. But my electrician knew what to look for. I'm guessing that if I unplugged everything from the circuit the VAC would be lower than with certain items running. |
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Post by ttocs on Aug 2, 2021 19:18:12 GMT -5
Yes. 3% of normal voltage in the USA is allowable. When we had the issue at a customer house there was 47V on the Ground so I called the barn builder to have his electrician come out to fix. In the meantime I had my electrician find the cause so I'd know what was going on. He was able to find the loose connection but we had to leave it that way until the other electrician came so he could then check everything. Luckily, being a barn, there aren't very many circuits for outlets. The problem was only discovered the first time another worker plugged a power tool into an outside outlet and it wouldn't work, but the circuit wasn't tripped. So I put my meter on it and was shocked (the expression "shocked", not electrically speaking) and perplexed. But my electrician knew what to look for. I'm guessing that if I unplugged everything from the circuit the VAC would be lower than with certain items running. Kind of, but you'd need to know what other circuit that circuit is "shared" with if it's configured like what I'm used to. But first let me explain that I'm in the Chicago area and we use metal conduit for all AC wiring, and each pair of Hot wires share a common Neutral wire, and the conduit often - but not always - provides a Ground. The outlets for my AV system are each wired as dedicated circuits with Isolated Ground, which means that a Ground wire runs from a groups of outlets all the way to the panel and the outlets are NOT connected to the metal box or conduit. Each pair of outlets are a pair of circuits, and both Hot wires share one Neutral wire. So to test your theory I would need to unplug the components plugged into a pair of outlets representing two circuits to unload both circuits. I really don't know how circuits are run and configured when using Romex because it's not allowed in the Counties I've worked in. edit: oops. I should've mentioned that each pair of outlets which share a Neutral can do so because they are on opposite phase lugs in the panel. IOW the breakers are adjacent to each other, one above the other, in the panel. |
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Post by DavidR on Aug 2, 2021 19:25:27 GMT -5
I was assuming that certain electrical items might spill over some voltage into the balance conductor/neutral as they operate but not enough to trip the breaker on going to ground.
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Post by ttocs on Aug 2, 2021 19:39:49 GMT -5
I was assuming that certain electrical items might spill over some voltage into the balance conductor/neutral as they operate but not enough to trip the breaker on going to ground. Ok, this is where it's a bit beyond my "comprenshion" as Cheech And Chong said in the Evelyn Woodhead Sped Redding Course. The amount of N-G voltage is not just simple load balancing but also voltage drop from wire length and gauge. A little of this, little of that, sort of thing. |
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Post by housetech on Aug 2, 2021 20:14:01 GMT -5
I may be incorrect Leonski, but GFI trip from current flow, not voltage (a potential difference)
DavidR- you're good to go!
When I mentioned the power supply problems we had with the new digital scanner product, we redesigned the P.S. not because it didn't work, but because it would be a pita to argue with customers that their AC power was the problem. We also install an isolator.
Digital electronics is ones & zeros- 0V & 5v. The 1 signal (5v) is reference to ground. If you have voltage floating on the reference line- ground, that voltage is read if it's high enough and you get lock-ups (due to a false "1" digit) and in severe cases, component failure.
Ever heard of "Jap reset"? Turn it off, unplug and reconnect- it's fixed. lol
NEC took a while to update the regulations and why cities have changed rules about updating a house for sale to meet code. It wasn't a problem decades ago- you turned on a light or ran a motor, no problem. Many houses didn't have grounded circuits. (remember the screw-in fuses?)
Digital electronics changed the world and one of the big improvement was power supply design. Some have asked why many electronic devices don't have a ground lead on the power cord. That's due to electricity issues, ground loops and the fact the PS has it's own ground by design. Power supply design has become a new science. The SMPS power supply design is possible because of digital and it's pretty ingenious.
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Post by housetech on Aug 2, 2021 20:46:30 GMT -5
I'm guessing that if I unplugged everything from the circuit the VAC would be lower than with certain items running. Kind of, but you'd need to know what other circuit that circuit is "shared" with if it's configured like what I'm used to. But first let me explain that I'm in the Chicago area and we use metal conduit for all AC wiring, and each pair of Hot wires share a common Neutral wire, and the conduit often - but not always - provides a Ground. The outlets for my AV system are each wired as dedicated circuits with Isolated Ground, which means that a Ground wire runs from a groups of outlets all the way to the panel and the outlets are NOT connected to the metal box or conduit. Each pair of outlets are a pair of circuits, and both Hot wires share one Neutral wire. So to test your theory I would need to unplug the components plugged into a pair of outlets representing two circuits to unload both circuits. I really don't know how circuits are run and configured when using Romex because it's not allowed in the Counties I've worked in. edit: oops. I should've mentioned that each pair of outlets which share a Neutral can do so because they are on opposite phase lugs in the panel. IOW the breakers are adjacent to each other, one above the other, in the panel. Two hots are a 240 volt circuit, it's different and code for industrial is also different than house voltage. Industrial can get away with things we home owners can not. If you are running two hots, one neutral and one ground wire or conduit that's a 240v system and NOT to be branched to two wall circuits of 120v, don't do it, against code. An isolated circuit is a separate breaker, separate hot, separate neutral & separate ground wire from the breaker panel to the wall outlet with no branch circuits. EXCELLENT, that's what you want. A branched circuit is the same but with parallel wiring to 2 to 4 wall sockets. The days of running two wires off a single breaker are now against code. In today's world, every 120v circuit breaker should be wired with a hot from the breaker and neutral and ground wires for that zone circuit to it's terminating end. Sharing neutrals and ground was sometimes ok decades ago, NOT TODAY. |
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Post by housetech on Aug 2, 2021 21:01:15 GMT -5
ttocs- 3% of normal voltage in the USA is allowable.
But definitely not advisable for electronics.
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Post by ttocs on Aug 2, 2021 21:51:11 GMT -5
Kind of, but you'd need to know what other circuit that circuit is "shared" with if it's configured like what I'm used to. But first let me explain that I'm in the Chicago area and we use metal conduit for all AC wiring, and each pair of Hot wires share a common Neutral wire, and the conduit often - but not always - provides a Ground. The outlets for my AV system are each wired as dedicated circuits with Isolated Ground, which means that a Ground wire runs from a groups of outlets all the way to the panel and the outlets are NOT connected to the metal box or conduit. Each pair of outlets are a pair of circuits, and both Hot wires share one Neutral wire. So to test your theory I would need to unplug the components plugged into a pair of outlets representing two circuits to unload both circuits. I really don't know how circuits are run and configured when using Romex because it's not allowed in the Counties I've worked in. edit: oops. I should've mentioned that each pair of outlets which share a Neutral can do so because they are on opposite phase lugs in the panel. IOW the breakers are adjacent to each other, one above the other, in the panel. Two hots are a 240 volt circuit, it's different and code for industrial is also different than house voltage. Industrial can get away with things we home owners can not. If you are running two hots, one neutral and one ground wire or conduit that's a 240v system and NOT to be branched to two wall circuits of 120v, don't do it, against code. An isolated circuit is a separate hot, separate neutral & separate ground wire from the breaker panel to the wall outlet with to branch circuits. EXCELLENT, that's what you want. A branched circuit is the same but with parallel wiring to 2 to 4 wall sockets. In today's world, every 120v circuit breaker should be wired with a hot from the breaker and neutral and ground wires for that zone circuit to it's terminating end. Sharing neutrals and ground was sometimes ok decades ago, NOT TODAY. Sorry for not being clear. Each circuit is one Hot and a shared Neutral with one other circuit. Two outlets in one box are two circuits. Each has its own Hot, and both share the Neutral. The Isolated Ground is also shared. One circuit breaker, one receptacle. Here's a diagram from NEC on which I painted out the first receptacle I'm not using, and this also is not for IG outlets, but the principle is the same as what I have for Hot/Neutral wiring. One receptacle is on Phase-A and the other is Phase-B, they both share a Neutral and IG.  |
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Post by ttocs on Aug 2, 2021 21:54:56 GMT -5
ttocs- 3% of normal voltage in the USA is allowable. But definitely not advisable for electronics. Correct. Especially for electronics like Emotiva makes. There's something I read a while back about a test a company performed and they noted that computers and electronics with digital power supplies would have problems with what's allowed. I'll try and find it, might have saved it somewhere. |
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