3000W Chinese Gensets Info.
professor95 wrote: EDIT ADDED 45/5/2013- When this thread started in March of 2005, I never expected to see it survive this long or amass the quantity of information that has been shared here. In...
Forum Discussion
Professor, and All,
I have purchased a Champion C46540 for RV use to power a Dometic 13.5BTU-hr A/C. I had previously borrowed a friends 7.5KW Generac and Man, was that noisy! Being a semi-retired EE, I did my calculations and came to the conclusion that 2KW would run the A/C excepting for start/rush current. However, all my professional work was with micro-Watts at the semiconductor chip level, and I had not acqainted myself with Rotating AC Machinery since schooldays in the early 1970s. I have spent long hours on the internet brushing up on inductiton motors, generators, etc, etc, leading up to this purchase... Long story short- the Champion met every expectation I had for it, and is much quieter of course than the Generac. This is a well-made machine!
THEN I found this thread.....an amazing compendium of information and distilled experience on the very subject I had been wrestling with! Thank you Prof and All! When I started, I was a little apprehensive that maybe an ELM3000 would have been a better choice....when I got to about page 200 when the C46540 becomes the primo recomendation, I was beaming! I am currently on page 422 and am quite interested in the noise abatement discussion.
I did some freefield noise measurements at 23ft on each side and got 68dbA(front) 67dbA(right) 72dBA(back) 72dBa(left) sides. I took a course in college on industrial noise abatement (sound fields are mathematically similar in important ways to electromagnetic fields, btw) and I find that most ideas I have had turns out to be anticipated and even prototyped in this thread as I read it. Excellent!
I do have a practical question. I would like to improve the starting characteristic of my Dometic 13.5K so that as it ages it does not become a problem for a genny, also so restarts can occur quickly. After study, I am clear on why I want a Electronic Potential Rely product instead of a PTC Relay product to accomplish this. I researched online to find that nearly every RV reference to this situation uses a Supco SPP6E. A product brochure here http://www.supco.com/images/pdfproductsheets/E%20Class%20Prod%20Sheet.pdf specifies 170Volt to 277Volt operation for the SPP6E on the first page and then 90Volt to 277Volt on the second page. I emailed Supco and the reply informed me that the SPP6E is for 240Volt operation, not 120Volt operation, and the brochure has a type problem on this spec. They also disavowed any testing of their product with the Dometic A/C.
This leads me to question whether users of the SPP6E in 120V applications are getting a true EPR functionality or whether the backup timeout feature of this same product is not actually the functionality they are depending on....?
To make matter worse, the Supco catalog http://www.supco.com/images/pdfs/2006%20HVAC%20Catalog%20HVAC%20Section%202-51.pdf gives 90Volt to 277Volt for ALL of the E-series products....
Since it matters what voltage the EPR senses and opens at, and the SPP4E is uniformly specified at 90V minimum, has any one used this one?
CAn anyone shed light on my confusion?
YHS,
rogerw
I have purchased a Champion C46540 for RV use to power a Dometic 13.5BTU-hr A/C. I had previously borrowed a friends 7.5KW Generac and Man, was that noisy! Being a semi-retired EE, I did my calculations and came to the conclusion that 2KW would run the A/C excepting for start/rush current. However, all my professional work was with micro-Watts at the semiconductor chip level, and I had not acqainted myself with Rotating AC Machinery since schooldays in the early 1970s. I have spent long hours on the internet brushing up on inductiton motors, generators, etc, etc, leading up to this purchase... Long story short- the Champion met every expectation I had for it, and is much quieter of course than the Generac. This is a well-made machine!
THEN I found this thread.....an amazing compendium of information and distilled experience on the very subject I had been wrestling with! Thank you Prof and All! When I started, I was a little apprehensive that maybe an ELM3000 would have been a better choice....when I got to about page 200 when the C46540 becomes the primo recomendation, I was beaming! I am currently on page 422 and am quite interested in the noise abatement discussion.
I did some freefield noise measurements at 23ft on each side and got 68dbA(front) 67dbA(right) 72dBA(back) 72dBa(left) sides. I took a course in college on industrial noise abatement (sound fields are mathematically similar in important ways to electromagnetic fields, btw) and I find that most ideas I have had turns out to be anticipated and even prototyped in this thread as I read it. Excellent!
I do have a practical question. I would like to improve the starting characteristic of my Dometic 13.5K so that as it ages it does not become a problem for a genny, also so restarts can occur quickly. After study, I am clear on why I want a Electronic Potential Rely product instead of a PTC Relay product to accomplish this. I researched online to find that nearly every RV reference to this situation uses a Supco SPP6E. A product brochure here http://www.supco.com/images/pdfproductsheets/E%20Class%20Prod%20Sheet.pdf specifies 170Volt to 277Volt operation for the SPP6E on the first page and then 90Volt to 277Volt on the second page. I emailed Supco and the reply informed me that the SPP6E is for 240Volt operation, not 120Volt operation, and the brochure has a type problem on this spec. They also disavowed any testing of their product with the Dometic A/C.
This leads me to question whether users of the SPP6E in 120V applications are getting a true EPR functionality or whether the backup timeout feature of this same product is not actually the functionality they are depending on....?
To make matter worse, the Supco catalog http://www.supco.com/images/pdfs/2006%20HVAC%20Catalog%20HVAC%20Section%202-51.pdf gives 90Volt to 277Volt for ALL of the E-series products....
Since it matters what voltage the EPR senses and opens at, and the SPP4E is uniformly specified at 90V minimum, has any one used this one?
CAn anyone shed light on my confusion?
YHS,
rogerw
