short circuit faulted
Member
- Location
- Columbia SC
Looking for the formula guru's & Persons familar with closed transition ATS units-
Connected load APX 320 Amperes System Voltage 480 3P4W ATS rated 600Amperes -
Normal and Generator OCPD 600 Ampere Frames, Draw Out Style Breakers with retrofited solid state trip units and fused protection. During routine testing of ATS unit. Nine units total with test consisitng of one sequentially operated ATS normal feed breaker being tripped to bring generator on line due to power loss with connected ATS transfering to generator with subsequent ATS units being exercised utilizing test button. Test button will force ATS to seek alternate source in closed or open transtion depending on unit setting - given this is a hospital all units set to closed transition. The actual problem, the worst possible ATS to have problem the Life Safety branch ATS attempts to close it closes out of phase angle blowing both the 600 ampere fuses for the breaker and the trigger fuse. Solid state trip records amperage reading of 7,000 amperes as well as the ATS unit.
The ATS units are a manufacturer's unit (Cummins) CPG - Model BTPC and fairly new for them given the mulitude of unrelated problems we encountered during commisioning process. But they remind me greatly of a Zenith unit which in my opinion makes an outstanding boat anchor - for what these cost, I could have purchased Russell and doubt very seriously I wpuld be making this post. Units meet specification intent, past that the customer nor myself or anywhere near happy with the units...customer has already started grumblings of wanting units changed out - it only took a year to get them installed between scheduling outages, equipment delay through submital processes, and them being retrofitted into a new 2 hour fire rated room to meet code.
Questions are as follows:
1. What formula will give me closed transiton connected time - 2 seperate sources normal and generator at 480V 3PH4W - number of cycles, connected out of phase to reflect the 7000A reading? I may have hammered that - but hopefully you get my intent.
2. Has anyone out there used this type switch or had this type problem with closed transiton switches.
ATS Service Tech was attempting to tell me yesterday, that they had nothing to do with breaker tripping and there may be a "parameters" issue to which I replied. I agree there is a parameters issue, why the hell is the unit not sensing correct phase alignment before closing out of phase - Oh and guess what happens when you buck phases...I believe it called a short, so yes the breaker is also on you.
Your input and experience is appreciated, have a great day all.
Steve
Connected load APX 320 Amperes System Voltage 480 3P4W ATS rated 600Amperes -
Normal and Generator OCPD 600 Ampere Frames, Draw Out Style Breakers with retrofited solid state trip units and fused protection. During routine testing of ATS unit. Nine units total with test consisitng of one sequentially operated ATS normal feed breaker being tripped to bring generator on line due to power loss with connected ATS transfering to generator with subsequent ATS units being exercised utilizing test button. Test button will force ATS to seek alternate source in closed or open transtion depending on unit setting - given this is a hospital all units set to closed transition. The actual problem, the worst possible ATS to have problem the Life Safety branch ATS attempts to close it closes out of phase angle blowing both the 600 ampere fuses for the breaker and the trigger fuse. Solid state trip records amperage reading of 7,000 amperes as well as the ATS unit.
The ATS units are a manufacturer's unit (Cummins) CPG - Model BTPC and fairly new for them given the mulitude of unrelated problems we encountered during commisioning process. But they remind me greatly of a Zenith unit which in my opinion makes an outstanding boat anchor - for what these cost, I could have purchased Russell and doubt very seriously I wpuld be making this post. Units meet specification intent, past that the customer nor myself or anywhere near happy with the units...customer has already started grumblings of wanting units changed out - it only took a year to get them installed between scheduling outages, equipment delay through submital processes, and them being retrofitted into a new 2 hour fire rated room to meet code.
Questions are as follows:
1. What formula will give me closed transiton connected time - 2 seperate sources normal and generator at 480V 3PH4W - number of cycles, connected out of phase to reflect the 7000A reading? I may have hammered that - but hopefully you get my intent.
2. Has anyone out there used this type switch or had this type problem with closed transiton switches.
ATS Service Tech was attempting to tell me yesterday, that they had nothing to do with breaker tripping and there may be a "parameters" issue to which I replied. I agree there is a parameters issue, why the hell is the unit not sensing correct phase alignment before closing out of phase - Oh and guess what happens when you buck phases...I believe it called a short, so yes the breaker is also on you.
Your input and experience is appreciated, have a great day all.
Steve