AR-XA switch cap question....aftermarket switch

dogwan

dogwan

Dogwan
I have an Early XA (actually it's a "TA" model) that I rebuilt with a DPST lighted switch. At the time it was easiest to wire the switch with both Live and Neutral lines running through it so that the light worked. I did not put any switch capacitor on it.

Used it for a while in a vintage SS system and "popping" from the switch was not an issue. The table sounds so good with an Ortofon FF15XE II cartridge and NOS stylus that I moved it into my dedicated room with tubed Pre- and Acoustats running on Servo amps. In this situ the popping is horrendous. If I forget to lower the volume and switch inputs the system sounds like it's going to blow up when I power down the TT. I've gotten used to leaving the TT running while swapping records. But, that precludes using a clamp since it is always spinning.

So, if I want to put in a switch cap how would I wire it since the return (neutral line) is also switched. If I put just on the Live connection will that be enough (would the neutral line also pop)? Should I put it across the Live and Neutral terminals before the switch? Do I need 2 caps, 1 for each pole so a slight current runs through it?

-Dogwan
 
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You probably need to go back to the original power configuration where 1 motor leg is always powered on across the switch. The neutral side line should attach at the motor phase cap. Right now i can't imagine the voltages your switch is seeing at on/off.
 
Switching the neutral is against the NEC. The only thing that needs to be switched is the line voltage. The capacitor goes across the two used contacts of the switch on the line side. The capacitor will allow some current to pass thru, and you can feel that on the motor, but it is not enough current to ever start the motor. This capacitor is what absorbs the make/break energy and stops the popping.

Back to your lighted switch, I doubt that the neutral is being switched (but don't ever do it anyway), but rather used to illuminate the built in lamp switch. These kinds of switches usually have 3 leads, so you can have the switch light when it's on (using the line pass-thru current) or have the switch lighted when the switch is off (then you need a neutral).
 
You ca buy specialized snubber device and put it between line and neutral on internal side from switch. Search Mouser or Digikey.
 
WaynerN said:
Switching the neutral is against the NEC. The only thing that needs to be switched is the line voltage. The capacitor goes across the two used contacts of the switch on the line side. The capacitor will allow some current to pass thru, and you can feel that on the motor, but it is not enough current to ever start the motor. This capacitor is what absorbs the make/break energy and stops the popping.

Back to your lighted switch, I doubt that the neutral is being switched (but don't ever do it anyway), but rather used to illuminate the built in lamp switch. These kinds of switches usually have 3 leads, so you can have the switch light when it's on (using the line pass-thru current) or have the switch lighted when the switch is off (then you need a neutral).
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Interesting, I looked it up and never realized that it was against code to switch neutral (chassis is fully grounded). I've seen other posts where advice was given to switch both for safety reasons on old tube equipment. Just don't ask me to find the posts, I've just read them.

My switch has 4 leads, I'm guessing that the 2 on the neutral side (labelled as such) are for determining whether it is lighted in the on or off position. I think I have my answer, just need to remove neutral from switch and run a line from that side of switch to connect to a 3 way connection where return leg of motor connects to neutral line on IEC inlet. That way light in switch is parallel with motor. And then of course put the capacitor across the live contacts on the switch.

FWIW, this deck has the original 2-motor setup which does not use a phase cap on the drive motor.
 
I would ask poster who referred to NEC give exact refernce to a section that disallows disconnect of BOTH hot and neutral wires. I am almost sure there is no such provision there.
 
for_p1 said:
I would ask poster who referred to NEC give exact refernce to a section that disallows disconnect of BOTH hot and neutral wires. I am almost sure there is no such provision there.
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My whole house, at the switches, is neutral disconnect. Dunno why. The whole development is that way....1958-59 build dates
 
I didn't think about it this morning, but on non-polarized plugs like the original XA and other vintage equipment the switch would be on either the Hot or Neutral leg depending on which way the plug is oriented. So, in reality the consumer would have no real control over whether the appliance meets this code, right? IF that's the case, then would it really be illegal to switch both legs? I'm guessing it's more important in household wiring so that HOT is disconnected at wall switch and circuit breaker for safety's sake and consistency.

Here's an article I found that references the NEC codes. I'm too lazy to go read the codes.http://www.mikeholt.com/mojonewsarchive/NEC-HTML/HTML/Article-404-Switches~20040624.php

I would like to know why it would be against code to completely isolate an appliance by switching both legs, especially if the chassis is grounded (unlike most vintage equipment)? However, I really just want to solve my popping problem. Since I have retro-fitted an IEC inlet and know which leg is always neutral I will take it off the switch and re-wire accordingly.
 
Because the neutral is the ground in a 2 wire system. In a three wire system the ground is really a safety ground. If you are an old timer, you may know that old hifi equipment had a potential to produce at least an electrical feel on metal parts when the non-polarized plug was in the wrong way.

Now days, the hot side of the line is fused and switched, leaving the neutral intact. If you should decide to put a polarized plug on your AR, that would be a great thing.

That is why we now have polarized plugs.
 
WaynerN said:
Because the neutral is the ground in a 2 wire system. In a three wire system the ground is really a safety ground. If you are an old timer, you may know that old hifi equipment had a potential to produce at least an electrical feel on metal parts when the non-polarized plug was in the wrong way.

Now days, the hot side of the line is fused and switched, leaving the neutral intact. If you should decide to put a polarized plug on your AR, that would be a great thing.

That is why we now have polarized plugs.
Click to expand...
You are wrong here. Neutral is NOT a ground. And should never be used as such. It means among other things that you should never connect chassis with neutral. And it also means that power switch SHOULD disconnect both neutral and hot wires.
 
You are wrong. It's a system ground. Earth ground is an extra "back-up" ground. Go look in your home's electrical circuit breaker box, where you will find the neutral and the (earth) grounds tied together. If that ain"t ground, then I don't know what is.
 
So then if Neutral and Ground are tied together at the breaker box why would it matter if the neutral is switched alongside the hot leg if the chassis is grounded? I might not have made it clear earlier, but I did add an IEC connector and all metal in the AR chassis is grounded through the house ground.

At this point it's just academics as I have solved my popping by rewiring the switch and adding a cap. However, the original question as to how to place a cap if the switch is breaking both neutral and hot was never answered.
 
Because most equipment does not have the 3rd leg ground. And as has been discussed, some do not have polarized plugs. We (in America) are living in an age of electrical development. Many older homes do not have the earth ground. Some homes still have fuses.

The mission is to keep people from getting electrocuted, yet this happens still in this day and age, every single day. People do stupid things, equipment fails in goofy ways, and other things that electrical designers can't imagine, happen.

Remember aluminum household wiring? How many folks died because of this? Hundreds, or maybe thousands? At any rate, keep your neutrals unswitched and unfused and all will be good.
 
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