http://ecmweb.com/content/avoid-instrum ... age-wiring
Nice article about grounding, ecm and metal conduit.
Ground Loop Article
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pngaudioguy
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Re: Ground Loop Article
Good article - thanks for sharing. The note on twisted pair got me to thinking, do we lose the benefit of using twisted pair if we use a setup as suggested on the wiki? One CAT5 cable with a single ground and 7 signals, for instance. I'm guessing the electromagnetic interference cancellation is less effective when each pair isn't being used as a "pair"? Anyone have experience and/or thoughts on that aspect?
Re: Ground Loop Article
I have always attacthed one of the pair to the temp guage. But I think a mistake as I aslo attached to the ground that I put in the box as well. I am re wiring and will only attach the wire to the Temp probe and not attach to the Chassis ground (an making a Ground Loop). Like a lot of things in doing the BCS wiring, I had never heard of this. I knew about electromagnetic interference and not routing wires near 110 vac lines or near compressors, but I thought the more grounds the better. I also going with the articles suggestion to use 18 awg twisted pair with a foil shield for my Temp runs with zero splices and place withing metal conduit for the Temp Sensor wires.
I have the M12 Patch cables from Brewers hardware. Not sure if they are twisted pair or not, but I an going to find out.
I have the M12 Patch cables from Brewers hardware. Not sure if they are twisted pair or not, but I an going to find out.
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pngaudioguy
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- Joined: Mon Nov 24, 2014 11:58 am
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Re: Ground Loop Article
From what I understand of what gets posted over and over, the ground between the BCS and the box SHOULD be connected to minimize reading fluctuations. There doesn't seem to be any "best practice" when you put the BCS in a separate enclosure, however.
The question I had was relating to the multi-pair between your high voltage box and your BCS box. Whether LAN or otherwise, are you running pairs of signals for that, or are you sharing one "common" for the temperature sensors? If they're shared, does that negate the effectiveness of the twisted pair cancellation? In your case, if you run the whole thing through a metal conduit, I suspect that detail becomes a moot point. Are you planning to run conduit from each of the kettles / data collection points all the way to the BCS?
The question I had was relating to the multi-pair between your high voltage box and your BCS box. Whether LAN or otherwise, are you running pairs of signals for that, or are you sharing one "common" for the temperature sensors? If they're shared, does that negate the effectiveness of the twisted pair cancellation? In your case, if you run the whole thing through a metal conduit, I suspect that detail becomes a moot point. Are you planning to run conduit from each of the kettles / data collection points all the way to the BCS?
Re: Ground Loop Article
I am in the process of totally re-wiring my brewery. I have purchased some “red neck” hot tub elements which are basically bucket heaters that you can submerse in the kettle then remove.
I have a small electric HLT that I use for HERMS.
I plan to heat my MLT and HLT the night before I brew and still use propane for the Boil. I have propane for my HLT but may not use that anymore as I can use the electric heater. I will have to see how it goes. Depending on how the heater works, I may still use Propane for the Sparge Water but from my first “trial” with just water, I think I can obtain the Sparge Temp during the Mash with the 1500w element alone.
So I have a “green” Hybrid System. It takes about 6 hours to heat 20 gallons of water from 60 degrees F to 162 degrees. I can do that in about an Hour & 15 with propane. The nice thing about Electric is that I feel safe doing that unattended. I would not do that with Propane.
I have run new 20 amp circuits with Wet Location outlets for all my Kettles (4) although I will only use elements on 3 for now. I also ran a couple of additional 15 amp circuits that will only be used for power to Outs from the BCS. Before I had some circuits that did other things besides providing power to the BCS. I still have some “shared” powers (for example my Alarm Light and Buzzer).
I am going to use 18 awg twisted pairs for the Temp Probes that will run from the BCS enclosure to a Metal Distribution box with M12 connectors. I run the Brewers Hardware 3 meter Patch cables to the probes. The 18 awg will be in ¾ metal conduits that will be grounded in BCS Box. It will cross all 110vac lines at 90 degrees. I checked the Metal Distribution box and there in no “ground” between the connectors and the wires in the M12 connectors.
I will only connect the “ground” to the common ground in the BCS Box and to the M12 Connector.
Previously, I had may have induced a ground loop as I ran a ground wire to the Distribution box and tied all the Temp Probes to that ground as well.
The power supply ground to the BCS ground.
I am not sure if a “ground” loop affects the control wires from the BCS to the SSRs but I will also ground them once in the BCS Box as well.
To say that I may not know what I am doing may be an understatement. In a past life I was a Pilot and somewhat technical but know little about electronics although “grounding” issues were a cause of some concerns in aviation, but I was not the person worrying about it unless it was broken.
Another issue is that I do not want to become an expert in Electronics. I want to brew! But I do want consistent results from consistent process. Since I have started to use the BCS, I am more consistent. Hopefully, this will help me even more. After this, I going to set up a BCS for fermentation control.
I have a small electric HLT that I use for HERMS.
I plan to heat my MLT and HLT the night before I brew and still use propane for the Boil. I have propane for my HLT but may not use that anymore as I can use the electric heater. I will have to see how it goes. Depending on how the heater works, I may still use Propane for the Sparge Water but from my first “trial” with just water, I think I can obtain the Sparge Temp during the Mash with the 1500w element alone.
So I have a “green” Hybrid System. It takes about 6 hours to heat 20 gallons of water from 60 degrees F to 162 degrees. I can do that in about an Hour & 15 with propane. The nice thing about Electric is that I feel safe doing that unattended. I would not do that with Propane.
I have run new 20 amp circuits with Wet Location outlets for all my Kettles (4) although I will only use elements on 3 for now. I also ran a couple of additional 15 amp circuits that will only be used for power to Outs from the BCS. Before I had some circuits that did other things besides providing power to the BCS. I still have some “shared” powers (for example my Alarm Light and Buzzer).
I am going to use 18 awg twisted pairs for the Temp Probes that will run from the BCS enclosure to a Metal Distribution box with M12 connectors. I run the Brewers Hardware 3 meter Patch cables to the probes. The 18 awg will be in ¾ metal conduits that will be grounded in BCS Box. It will cross all 110vac lines at 90 degrees. I checked the Metal Distribution box and there in no “ground” between the connectors and the wires in the M12 connectors.
I will only connect the “ground” to the common ground in the BCS Box and to the M12 Connector.
Previously, I had may have induced a ground loop as I ran a ground wire to the Distribution box and tied all the Temp Probes to that ground as well.
The power supply ground to the BCS ground.
I am not sure if a “ground” loop affects the control wires from the BCS to the SSRs but I will also ground them once in the BCS Box as well.
To say that I may not know what I am doing may be an understatement. In a past life I was a Pilot and somewhat technical but know little about electronics although “grounding” issues were a cause of some concerns in aviation, but I was not the person worrying about it unless it was broken.
Another issue is that I do not want to become an expert in Electronics. I want to brew! But I do want consistent results from consistent process. Since I have started to use the BCS, I am more consistent. Hopefully, this will help me even more. After this, I going to set up a BCS for fermentation control.