Hi I'm an electronic technician first and sometime industrial power/controls electrician. Entry into the technical fields through completion of 2500 class hours via two vocational schools, about 19 years ago in analog/digital/wireless communications electronics. My electrical experience is building some harbor and aircraft cranes, refits of natural gas turbine plants and their associated controls.
This question pertains to a field I have less experience with; I'm not sure whether it falls under agricultural, commercial, or residential electricity.
Here in Southeastern Arizona there are greenhouses for raising vegetables, at times some of them for commercial sales. A man's asked me if I will wire one. On inspection of parts he's acquired found some Intermatic T104 water heater timers. He wants these to run pumps and a 240 volt ventilation fan he has mounted at one end.
Looking these up I find the T104 timer to be 240 volt clock controlled but there's a neutral terminal so I assume they'll switch 120 when needed.
Handling one I noticed the snap in timer module seems to be the sole grounding point for these units. No other ground points seemed in evidence on the the enclosure, nor the switched power terminal strip. Online manuals as well seem to indicate no other ground points.
I called an electrical contractor friend. He said he thought the single removable module ground point is the extent of grounding needed since the snap in timer isn't permanently mounted. He is busy, his business a one man shop so felt I could ask here.
I do not have a NEC codebook any longer, at least I can't find it. I think I loaned it out and forgot to get it back.
Could someone
(1) verify that due to the timer module being of removable configuration, the only ground required for the complete device is the mounting plate for it's timer component
(2)confirm my intuitive conclusion that were the timer module permanently mounted, the device would be grounded as any other typical electrical appliance, with timer motor grounded to the enclosure via an enclosure grounding lug (this isn't a real world consideration - just a question on my part - and the actual driving factor leading me to post this question)
(3)does the agricultural, possibly commercial environment impact bonding method consideration? It seems it should; however it's on a residential property with no assurance it will be used for commercial purposes. The hothouse is not connected to the home or any other structure but will be fed from the home's 200 amp service which was upgraded from 100 previous to my becoming involved.
(4) refer me to relevant, individual sections of the NEC which dictate considerations governing permanently mounted motors/modules, vs removable ones such as these?
Thank you all very much in advance.
I will check back and am grateful for any discussion that will help me know more about this. As I said the driving consideration for posting here was curiosity over rules relevant to permanently mounted vs. removable timer modules such as these.
Toward the end of this I see ordering a new NEC code book in my future. Timely discussion in the meanwhile will mean being more well apprised until I have one in my possession and can look through it for pertinent reference sections.
By the way through the years I've enjoyed reading here and appreciate the concise & professional nature of the conversations I've had the pleasure to review
This question pertains to a field I have less experience with; I'm not sure whether it falls under agricultural, commercial, or residential electricity.
Here in Southeastern Arizona there are greenhouses for raising vegetables, at times some of them for commercial sales. A man's asked me if I will wire one. On inspection of parts he's acquired found some Intermatic T104 water heater timers. He wants these to run pumps and a 240 volt ventilation fan he has mounted at one end.
Looking these up I find the T104 timer to be 240 volt clock controlled but there's a neutral terminal so I assume they'll switch 120 when needed.
Handling one I noticed the snap in timer module seems to be the sole grounding point for these units. No other ground points seemed in evidence on the the enclosure, nor the switched power terminal strip. Online manuals as well seem to indicate no other ground points.
I called an electrical contractor friend. He said he thought the single removable module ground point is the extent of grounding needed since the snap in timer isn't permanently mounted. He is busy, his business a one man shop so felt I could ask here.
I do not have a NEC codebook any longer, at least I can't find it. I think I loaned it out and forgot to get it back.
Could someone
(1) verify that due to the timer module being of removable configuration, the only ground required for the complete device is the mounting plate for it's timer component
(2)confirm my intuitive conclusion that were the timer module permanently mounted, the device would be grounded as any other typical electrical appliance, with timer motor grounded to the enclosure via an enclosure grounding lug (this isn't a real world consideration - just a question on my part - and the actual driving factor leading me to post this question)
(3)does the agricultural, possibly commercial environment impact bonding method consideration? It seems it should; however it's on a residential property with no assurance it will be used for commercial purposes. The hothouse is not connected to the home or any other structure but will be fed from the home's 200 amp service which was upgraded from 100 previous to my becoming involved.
(4) refer me to relevant, individual sections of the NEC which dictate considerations governing permanently mounted motors/modules, vs removable ones such as these?
Thank you all very much in advance.
I will check back and am grateful for any discussion that will help me know more about this. As I said the driving consideration for posting here was curiosity over rules relevant to permanently mounted vs. removable timer modules such as these.
Toward the end of this I see ordering a new NEC code book in my future. Timely discussion in the meanwhile will mean being more well apprised until I have one in my possession and can look through it for pertinent reference sections.
By the way through the years I've enjoyed reading here and appreciate the concise & professional nature of the conversations I've had the pleasure to review
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