Contactor that doesn't hum?

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Jraef

Jraef

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Siemens makes a small contactor called a 3TG10 that is designed to be ”hum free”. I helped engineer a project in Vegas for the Wynn hotel, every room as a lighting contactor in the wall, guests complained about the hum. We tried several brands, the Siemens was the only one they couldn’t hear. The only problem is, they are only rated for 8.4A. That was enough for my project because it was all LED lighting.

 
Besoeker3

Besoeker3

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Jraef said:
Siemens makes a small contactor called a 3TG10 that is designed to be ”hum free”. I helped engineer a project in Vegas for the Wynn hotel, every room as a lighting contactor in the wall, guests complained about the hum. We tried several brands, the Siemens was the only one they couldn’t hear. The only problem is, they are only rated for 8.4A. That was enough for my project because it was all LED lighting.

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V AC, 45...450 Hz
Interesting.
Looks like it could be an AC to DC conversion.
 
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jaggedben

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So just to be clear, for everyone recommending the RIBs, you've had no problems with hum on the non-latching relays?

Thanks for all the replies.
 
LarryFine

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Terminator5047

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jaggedben said:
Gotta model suggestion? Those seem to cost a lot. Would love to find something that costs twice as much as the eaton contactor instead of 6-8 times.
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I have know idea what you are trying to do there are literally 100s of different RIBS if you are doing anything with LED close to the 20amp rating go with the 30amp becuase the inrush on LED is crazy and will mess up the contacts
 
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jaggedben

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hillbilly1 said:
I believe the relay coil inside it is dc, never heard one hum. It is driven off a printed circuit board.
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Interesting. As I'm looking at the RIB models they seem to allow both AC and DC coil input, so I wonder if that circuit board has a rectifier. That makes it a nice solution since I already have an AC transformer driving this and would prefer not to have to supply another device.
 
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jaggedben

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Terminator5047 said:
I have know idea what you are trying to do there are literally 100s of different RIBS if you are doing anything with LED close to the 20amp rating go with the 30amp becuase the inrush on LED is crazy and will mess up the contacts
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I was asking after the solid state relays. But I'm leaning toward trying the RIB given all the recommendations. The load is a heat pump, 15A 240V 1Ph. It's variable speed without a high LRA so I think I'm fine with 20A resitive rating, or even 15.
 
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Terminator5047

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jaggedben said:
I was asking after the solid state relays. But I'm leaning toward trying the RIB given all the recommendations. The load is a heat pump, 15A 240V 1Ph. It's variable speed without a high LRA so I think I'm fine with 20A resitive rating, or even 15.
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Grainger is a rip off as we all know try to order some place else but the company function devices has a ton of useful stuff such as ribs and powe lt supplies you should check out their product line
 
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hillbilly1

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North Georgia mountains
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Terminator5047 said:
Grainger is a rip off as we all know try to order some place else but the company function devices has a ton of useful stuff such as ribs and powe lt supplies you should check out their product line
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Yes, they are much higher, but unlike regular supply houses, they have it in stock if you need it right now. If you have time to wait though, it is much cheaper elsewhere.
 
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BIGPOWERMAN

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New York, NY USA
I would first check the coil voltage to see if it is correct and should be within 10%. The control transformer feeding it could be tapped incorrectly
and the coil voltage is too high causing saturation when energized and the buzzing noise. Measure first to see if it is correct. It may not be the
contactor. If it is mounted on thin metal the buzzing may be coming from that. of you loosen the contactor off the surface and the noise goes away
then the magnetic field may be vibrating the sheet steel. Thin foam rubber or something under the contator may solve the issue for your customer
DC contactors are getting harder to get these days and you need to get the DC to run it. Not so easy if other items also use the 24VAC.
DC not good for thermostat relay contacts and you need to snubber the flyback energy voltage from the contactor coil when it turns off.
The solid state relay idea also sounds like a good idea though providing cost not an issue,
 
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