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Main
Date: 23 Jun 2006 19:17:19
From: Jeff Davis - Charter
Subject: OT: SSR questions
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I was trying to PID my electric smoker using only parts I had on hand: cheap
PID controller with 5 vdc ssr output, 30 amp power relay with 120v coil and
5 amp ssr with 5 vdc input and 120 v output.
I knew my 5 amp SSR was not enough to handle the 13 amp load from the
heating element in the smoker so I tried using the 120 v output from that
SSR to control the power relay. However (I guess) the power relay coil was
not enough "load" and the SSR would not turn off the relay.
Ultimately I connected a 15 watt glue gun in parallel with the coil on the
power relay and everything worked fine.
My question is, how much load do I need to make the SSR switch and would a
power handling resistor work as well? Although I don't currently have a
better use for the glue gun.
Or is there a better solution I can implement using my existing parts?
TIA,
Jeff (Can't have too many crimp-on connectors)
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Date: 24 Jun 2006 05:58:25
From: Phil Paintin
Subject: Re: OT: SSR questions
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Jeff Davis - Charter wrote:
> I was trying to PID my electric smoker using only parts I had on hand: cheap
> PID controller with 5 vdc ssr output, 30 amp power relay with 120v coil and
> 5 amp ssr with 5 vdc input and 120 v output.
>
> I knew my 5 amp SSR was not enough to handle the 13 amp load from the
> heating element in the smoker so I tried using the 120 v output from that
> SSR to control the power relay. However (I guess) the power relay coil was
> not enough "load" and the SSR would not turn off the relay.
>
> Ultimately I connected a 15 watt glue gun in parallel with the coil on the
> power relay and everything worked fine.
>
> My question is, how much load do I need to make the SSR switch and would a
> power handling resistor work as well? Although I don't currently have a
> better use for the glue gun.
>
> Or is there a better solution I can implement using my existing parts?
>
Jeff, do you have the make and model of the SSR to help with looking up
the specs ?
SSRs don't like inductive loads (like the coil of your mechanical
relay) in general, and the manufacturer will probably recommend using
an R-C 'snubber' network, at least with larger inductive loads. Not
sure what the situation is with small inductive loads . . .
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Date: 24 Jun 2006 13:23:23
From: Jeff Davis - Charter
Subject: Re: OT: SSR questions
|
On 6/24/06 7:58 AM, in article
1151153905.367229.104550@i40g2000cwc.googlegroups.com, "Phil Paintin"
<charneybarn@yahoo.com > wrote:
>
> Jeff Davis - Charter wrote:
>> I was trying to PID my electric smoker using only parts I had on hand: cheap
>> PID controller with 5 vdc ssr output, 30 amp power relay with 120v coil and
>> 5 amp ssr with 5 vdc input and 120 v output.
>>
>> I knew my 5 amp SSR was not enough to handle the 13 amp load from the
>> heating element in the smoker so I tried using the 120 v output from that
>> SSR to control the power relay. However (I guess) the power relay coil was
>> not enough "load" and the SSR would not turn off the relay.
>>
>> Ultimately I connected a 15 watt glue gun in parallel with the coil on the
>> power relay and everything worked fine.
>>
>> My question is, how much load do I need to make the SSR switch and would a
>> power handling resistor work as well? Although I don't currently have a
>> better use for the glue gun.
>>
>> Or is there a better solution I can implement using my existing parts?
>>
>
> Jeff, do you have the make and model of the SSR to help with looking up
> the specs ?
>
> SSRs don't like inductive loads (like the coil of your mechanical
> relay) in general, and the manufacturer will probably recommend using
> an R-C 'snubber' network, at least with larger inductive loads. Not
> sure what the situation is with small inductive loads . . .
>
Phil, It's an Omron G3NA-210B. What's an R-C snubber?
Jeff
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Date: 25 Jun 2006 06:36:50
From: daveb
Subject: Re: OT: SSR questions
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<< The cleanest solution would be to just get a higher current SSR on
ebay
> -- 25 or 40A. .......>>
Phil is correct .
With 4 other benefits: You could cut the cycle time on the controller
allowing tighter control, and 2) it'd be a WHOLE LOT quieter!! 3)
would probably reduce interference with radios and TV, etc. 4) won't
wear out.
one like this would be great:
http://cgi.ebay.com/Continental-Industries-Solid-State-Relay_W0QQitem...
Dave
Phil Paintin wrote:
> Jeff Davis - Charter wrote:
> > On 6/24/06 7:58 AM, in article
> > 1151153905.367229.104550@i40g2000cwc.googlegroups.com, "Phil Paintin"
> > <charneybarn@yahoo.com> wrote:
> >
> > >
> > > Jeff Davis - Charter wrote:
> > >> I was trying to PID my electric smoker using only parts I had on hand: cheap
> > >> PID controller with 5 vdc ssr output, 30 amp power relay with 120v coil and
> > >> 5 amp ssr with 5 vdc input and 120 v output.
> > >>
> > >> I knew my 5 amp SSR was not enough to handle the 13 amp load from the
> > >> heating element in the smoker so I tried using the 120 v output from that
> > >> SSR to control the power relay. However (I guess) the power relay coil was
> > >> not enough "load" and the SSR would not turn off the relay.
> > >>
> > >> Ultimately I connected a 15 watt glue gun in parallel with the coil on the
> > >> power relay and everything worked fine.
> > >>
> > >> My question is, how much load do I need to make the SSR switch and would a
> > >> power handling resistor work as well? Although I don't currently have a
> > >> better use for the glue gun.
> > >>
> > >> Or is there a better solution I can implement using my existing parts?
> > >>
> > >
> > > Jeff, do you have the make and model of the SSR to help with looking up
> > > the specs ?
> > >
> > > SSRs don't like inductive loads (like the coil of your mechanical
> > > relay) in general, and the manufacturer will probably recommend using
> > > an R-C 'snubber' network, at least with larger inductive loads. Not
> > > sure what the situation is with small inductive loads . . .
> > >
> > Phil, It's an Omron G3NA-210B. What's an R-C snubber?
>
> A snubber network is a small resistor + capacitor circuit supplied as a
> module to connect across the output of SSRs to damp out the current
> surges when switching off an inductive or capacitive load. These
> surges are what cause the sparking across mechanical relay contacts
> when they try to break the current to switch off a load. Omron don't
> mention one for this unit.
>
> Your relay is apparently 10 amps capacity, though that doesn't change
> anything here. Omron quotes a leakage current of up to 5 mA which
> might be enough to keep the mechanical relay coil energised when
> combined with the fact that it's an inductive load.
>
> The cleanest solution would be to just get a higher current SSR on ebay
> -- 25 or 40A. If you don't want to buy anything else but do want your
> glue gun back, a low-wattage lamp would do in its place.
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Date: 25 Jun 2006 06:34:14
From: daveb
Subject: Re: OT: SSR questions
|
The cleanest solution would be to just get a higher current SSR on
ebay
> -- 25 or 40A. .......
Phil is correct .
With 4 other benefits: You could cut the cycle time on the controller
allowing tighter control, and 2) it'd be a WHOLE LOT quieter!! 3)
would probably reduce interference with radios and TV, etc. $0 won't
wear out.
one like this would be great:
http://cgi.ebay.com/Continental-Industries-Solid-State-Relay_W0QQitemZ250001190769QQihZ015QQcategoryZ78207QQrdZ1QQcmdZViewItem
Dave
Phil Paintin wrote:
> Jeff Davis - Charter wrote:
> > On 6/24/06 7:58 AM, in article
> > 1151153905.367229.104550@i40g2000cwc.googlegroups.com, "Phil Paintin"
> > <charneybarn@yahoo.com> wrote:
> >
> > >
> > > Jeff Davis - Charter wrote:
> > >> I was trying to PID my electric smoker using only parts I had on hand: cheap
> > >> PID controller with 5 vdc ssr output, 30 amp power relay with 120v coil and
> > >> 5 amp ssr with 5 vdc input and 120 v output.
> > >>
> > >> I knew my 5 amp SSR was not enough to handle the 13 amp load from the
> > >> heating element in the smoker so I tried using the 120 v output from that
> > >> SSR to control the power relay. However (I guess) the power relay coil was
> > >> not enough "load" and the SSR would not turn off the relay.
> > >>
> > >> Ultimately I connected a 15 watt glue gun in parallel with the coil on the
> > >> power relay and everything worked fine.
> > >>
> > >> My question is, how much load do I need to make the SSR switch and would a
> > >> power handling resistor work as well? Although I don't currently have a
> > >> better use for the glue gun.
> > >>
> > >> Or is there a better solution I can implement using my existing parts?
> > >>
> > >
> > > Jeff, do you have the make and model of the SSR to help with looking up
> > > the specs ?
> > >
> > > SSRs don't like inductive loads (like the coil of your mechanical
> > > relay) in general, and the manufacturer will probably recommend using
> > > an R-C 'snubber' network, at least with larger inductive loads. Not
> > > sure what the situation is with small inductive loads . . .
> > >
> > Phil, It's an Omron G3NA-210B. What's an R-C snubber?
>
> A snubber network is a small resistor + capacitor circuit supplied as a
> module to connect across the output of SSRs to damp out the current
> surges when switching off an inductive or capacitive load. These
> surges are what cause the sparking across mechanical relay contacts
> when they try to break the current to switch off a load. Omron don't
> mention one for this unit.
>
> Your relay is apparently 10 amps capacity, though that doesn't change
> anything here. Omron quotes a leakage current of up to 5 mA which
> might be enough to keep the mechanical relay coil energised when
> combined with the fact that it's an inductive load.
>
> The cleanest solution would be to just get a higher current SSR on ebay
> -- 25 or 40A. If you don't want to buy anything else but do want your
> glue gun back, a low-wattage lamp would do in its place.
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Date: 25 Jun 2006 03:39:31
From: Phil Paintin
Subject: Re: OT: SSR questions
|
Jeff Davis - Charter wrote:
> On 6/24/06 7:58 AM, in article
> 1151153905.367229.104550@i40g2000cwc.googlegroups.com, "Phil Paintin"
> <charneybarn@yahoo.com> wrote:
>
> >
> > Jeff Davis - Charter wrote:
> >> I was trying to PID my electric smoker using only parts I had on hand: cheap
> >> PID controller with 5 vdc ssr output, 30 amp power relay with 120v coil and
> >> 5 amp ssr with 5 vdc input and 120 v output.
> >>
> >> I knew my 5 amp SSR was not enough to handle the 13 amp load from the
> >> heating element in the smoker so I tried using the 120 v output from that
> >> SSR to control the power relay. However (I guess) the power relay coil was
> >> not enough "load" and the SSR would not turn off the relay.
> >>
> >> Ultimately I connected a 15 watt glue gun in parallel with the coil on the
> >> power relay and everything worked fine.
> >>
> >> My question is, how much load do I need to make the SSR switch and would a
> >> power handling resistor work as well? Although I don't currently have a
> >> better use for the glue gun.
> >>
> >> Or is there a better solution I can implement using my existing parts?
> >>
> >
> > Jeff, do you have the make and model of the SSR to help with looking up
> > the specs ?
> >
> > SSRs don't like inductive loads (like the coil of your mechanical
> > relay) in general, and the manufacturer will probably recommend using
> > an R-C 'snubber' network, at least with larger inductive loads. Not
> > sure what the situation is with small inductive loads . . .
> >
> Phil, It's an Omron G3NA-210B. What's an R-C snubber?
A snubber network is a small resistor + capacitor circuit supplied as a
module to connect across the output of SSRs to damp out the current
surges when switching off an inductive or capacitive load. These
surges are what cause the sparking across mechanical relay contacts
when they try to break the current to switch off a load. Omron don't
mention one for this unit.
Your relay is apparently 10 amps capacity, though that doesn't change
anything here. Omron quotes a leakage current of up to 5 mA which
might be enough to keep the mechanical relay coil energised when
combined with the fact that it's an inductive load.
The cleanest solution would be to just get a higher current SSR on ebay
-- 25 or 40A. If you don't want to buy anything else but do want your
glue gun back, a low-wattage lamp would do in its place.
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Date: 25 Jun 2006 11:42:11
From: Jeff Davis - Charter
Subject: Re: OT: SSR questions
|
On 6/25/06 5:39 AM, in article
1151231971.517899.295350@p79g2000cwp.googlegroups.com, "Phil Paintin"
<charneybarn@yahoo.com > wrote:
>
> Jeff Davis - Charter wrote:
>> On 6/24/06 7:58 AM, in article
>> 1151153905.367229.104550@i40g2000cwc.googlegroups.com, "Phil Paintin"
>> <charneybarn@yahoo.com> wrote:
>>
>>>
>>> Jeff Davis - Charter wrote:
>>>> I was trying to PID my electric smoker using only parts I had on hand:
>>>> cheap
>>>> PID controller with 5 vdc ssr output, 30 amp power relay with 120v coil and
>>>> 5 amp ssr with 5 vdc input and 120 v output.
>>>>
>>>> I knew my 5 amp SSR was not enough to handle the 13 amp load from the
>>>> heating element in the smoker so I tried using the 120 v output from that
>>>> SSR to control the power relay. However (I guess) the power relay coil was
>>>> not enough "load" and the SSR would not turn off the relay.
>>>>
>>>> Ultimately I connected a 15 watt glue gun in parallel with the coil on the
>>>> power relay and everything worked fine.
>>>>
>>>> My question is, how much load do I need to make the SSR switch and would a
>>>> power handling resistor work as well? Although I don't currently have a
>>>> better use for the glue gun.
>>>>
>>>> Or is there a better solution I can implement using my existing parts?
>>>>
>>>
>>> Jeff, do you have the make and model of the SSR to help with looking up
>>> the specs ?
>>>
>>> SSRs don't like inductive loads (like the coil of your mechanical
>>> relay) in general, and the manufacturer will probably recommend using
>>> an R-C 'snubber' network, at least with larger inductive loads. Not
>>> sure what the situation is with small inductive loads . . .
>>>
>> Phil, It's an Omron G3NA-210B. What's an R-C snubber?
>
> A snubber network is a small resistor + capacitor circuit supplied as a
> module to connect across the output of SSRs to damp out the current
> surges when switching off an inductive or capacitive load. These
> surges are what cause the sparking across mechanical relay contacts
> when they try to break the current to switch off a load. Omron don't
> mention one for this unit.
>
> Your relay is apparently 10 amps capacity, though that doesn't change
> anything here. Omron quotes a leakage current of up to 5 mA which
> might be enough to keep the mechanical relay coil energised when
> combined with the fact that it's an inductive load.
>
> The cleanest solution would be to just get a higher current SSR on ebay
> -- 25 or 40A. If you don't want to buy anything else but do want your
> glue gun back, a low-wattage lamp would do in its place.
>
Phil - thanks for your help. I probably will buy a larger SSR but I needed
to have it working on Saturday for a BBQ and at 4:00 on Friday the existing
parts were the best I could do. The biggest disadvantage to me was all the
extra wiring I had to do to accommodate SSR, power relay and glue gun. That
in itself is a good reason for a larger SSR.
Thanks again,
Jeff
PS: I just put a bid in on one on ebay.
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Date: 25 Jun 2006 07:44:21
From: Jack Denver
Subject: Re: OT: SSR questions
|
Maybe something like a 7W night light bulb. This would double as an
indicator lamp so you'd know when the element is on.
http://www.source4lights.com/product.aspx?prod=148&bbaff=6250094
"Phil Paintin" <charneybarn@yahoo.com > wrote in message
news:1151231971.517899.295350@p79g2000cwp.googlegroups.com...
>
> Jeff Davis - Charter wrote:
>> On 6/24/06 7:58 AM, in article
>> 1151153905.367229.104550@i40g2000cwc.googlegroups.com, "Phil Paintin"
>> <charneybarn@yahoo.com> wrote:
>>
>> >
>> > Jeff Davis - Charter wrote:
>> >> I was trying to PID my electric smoker using only parts I had on hand:
>> >> cheap
>> >> PID controller with 5 vdc ssr output, 30 amp power relay with 120v
>> >> coil and
>> >> 5 amp ssr with 5 vdc input and 120 v output.
>> >>
>> >> I knew my 5 amp SSR was not enough to handle the 13 amp load from the
>> >> heating element in the smoker so I tried using the 120 v output from
>> >> that
>> >> SSR to control the power relay. However (I guess) the power relay coil
>> >> was
>> >> not enough "load" and the SSR would not turn off the relay.
>> >>
>> >> Ultimately I connected a 15 watt glue gun in parallel with the coil on
>> >> the
>> >> power relay and everything worked fine.
>> >>
>> >> My question is, how much load do I need to make the SSR switch and
>> >> would a
>> >> power handling resistor work as well? Although I don't currently have
>> >> a
>> >> better use for the glue gun.
>> >>
>> >> Or is there a better solution I can implement using my existing parts?
>> >>
>> >
>> > Jeff, do you have the make and model of the SSR to help with looking up
>> > the specs ?
>> >
>> > SSRs don't like inductive loads (like the coil of your mechanical
>> > relay) in general, and the manufacturer will probably recommend using
>> > an R-C 'snubber' network, at least with larger inductive loads. Not
>> > sure what the situation is with small inductive loads . . .
>> >
>> Phil, It's an Omron G3NA-210B. What's an R-C snubber?
>
> A snubber network is a small resistor + capacitor circuit supplied as a
> module to connect across the output of SSRs to damp out the current
> surges when switching off an inductive or capacitive load. These
> surges are what cause the sparking across mechanical relay contacts
> when they try to break the current to switch off a load. Omron don't
> mention one for this unit.
>
> Your relay is apparently 10 amps capacity, though that doesn't change
> anything here. Omron quotes a leakage current of up to 5 mA which
> might be enough to keep the mechanical relay coil energised when
> combined with the fact that it's an inductive load.
>
> The cleanest solution would be to just get a higher current SSR on ebay
> -- 25 or 40A. If you don't want to buy anything else but do want your
> glue gun back, a low-wattage lamp would do in its place.
>
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Date: 25 Jun 2006 11:48:05
From: Jeff Davis - Charter
Subject: Re: OT: SSR questions
|
Thanks Jack, that's a good idea. I've just placed a bid on a larger SSR on
ebay so that is probably the cleanest solution - keep my bread boarding to a
minium.
On 6/25/06 6:44 AM, in article prydnSJmNcOL6gPZnZ2dnUVZ_tGdnZ2d@comcast.com,
"Jack Denver" <nunuvyer@netscape.net > wrote:
> Maybe something like a 7W night light bulb. This would double as an
> indicator lamp so you'd know when the element is on.
>
> http://www.source4lights.com/product.aspx?prod=148&bbaff=6250094
>
>
> "Phil Paintin" <charneybarn@yahoo.com> wrote in message
> news:1151231971.517899.295350@p79g2000cwp.googlegroups.com...
>>
>> Jeff Davis - Charter wrote:
>>> On 6/24/06 7:58 AM, in article
>>> 1151153905.367229.104550@i40g2000cwc.googlegroups.com, "Phil Paintin"
>>> <charneybarn@yahoo.com> wrote:
>>>
>>>>
>>>> Jeff Davis - Charter wrote:
>>>>> I was trying to PID my electric smoker using only parts I had on hand:
>>>>> cheap
>>>>> PID controller with 5 vdc ssr output, 30 amp power relay with 120v
>>>>> coil and
>>>>> 5 amp ssr with 5 vdc input and 120 v output.
>>>>>
>>>>> I knew my 5 amp SSR was not enough to handle the 13 amp load from the
>>>>> heating element in the smoker so I tried using the 120 v output from
>>>>> that
>>>>> SSR to control the power relay. However (I guess) the power relay coil
>>>>> was
>>>>> not enough "load" and the SSR would not turn off the relay.
>>>>>
>>>>> Ultimately I connected a 15 watt glue gun in parallel with the coil on
>>>>> the
>>>>> power relay and everything worked fine.
>>>>>
>>>>> My question is, how much load do I need to make the SSR switch and
>>>>> would a
>>>>> power handling resistor work as well? Although I don't currently have
>>>>> a
>>>>> better use for the glue gun.
>>>>>
>>>>> Or is there a better solution I can implement using my existing parts?
>>>>>
>>>>
>>>> Jeff, do you have the make and model of the SSR to help with looking up
>>>> the specs ?
>>>>
>>>> SSRs don't like inductive loads (like the coil of your mechanical
>>>> relay) in general, and the manufacturer will probably recommend using
>>>> an R-C 'snubber' network, at least with larger inductive loads. Not
>>>> sure what the situation is with small inductive loads . . .
>>>>
>>> Phil, It's an Omron G3NA-210B. What's an R-C snubber?
>>
>> A snubber network is a small resistor + capacitor circuit supplied as a
>> module to connect across the output of SSRs to damp out the current
>> surges when switching off an inductive or capacitive load. These
>> surges are what cause the sparking across mechanical relay contacts
>> when they try to break the current to switch off a load. Omron don't
>> mention one for this unit.
>>
>> Your relay is apparently 10 amps capacity, though that doesn't change
>> anything here. Omron quotes a leakage current of up to 5 mA which
>> might be enough to keep the mechanical relay coil energised when
>> combined with the fact that it's an inductive load.
>>
>> The cleanest solution would be to just get a higher current SSR on ebay
>> -- 25 or 40A. If you don't want to buy anything else but do want your
>> glue gun back, a low-wattage lamp would do in its place.
>>
>
>
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