FacEngrPE: IEEE 45 is IBR is IBRed into 46 CFR Sub J as is the NFPA 70 (NEC). Mostly they all work together, although can be circuitous at times, but the biggest conflict comes with the interpretation and enforcement. In the case above of the LVP v. LVR, I believe that the CG lost perspective...
FacEngrPE: Existing unit and existing application was for Sub L OSV. We converted to Sub H Passenger - however, 46 CFR 111.70-3 applies in either case. Existing the fire pump controllers were LVP, however, they included two additional start/stop stations (remote) at the ECC & Bridge, in...
Yes, marine application and Coast Guard is the AHJ. Requirements are provided in 46 CFR Sub J and no specific listing requirements identified for fire pump motor controllers. Yes, certain construction requirements wrt branch feeders, breakers, etc, but nothing governing controls. That being...
Thanks Waross and concur. The mechanical latching relay solution is what we will use to provide us with LVR (TWO WIRE CONTROL) service while permitting re-use of the two existing remote stations controls. Thanks for your help!
Best
Jim
Yes, thanks - the residential solution with the "traveler" conductor did cross my mind. I came up with another means that would allow us to reuse the existing momentary switch as the local and two remote stations (with just some simple rewiring) by employing a mechanical latching relay, dual...
Waross - Thank you for your comment. I think I could have framed my question better. OK, my understanding of LVR & LVRE both mean restart upon resumption of power. The typical LVR circuits apply maintained (non-momentary) switches to either engage a contactor or across the line (LVRE for...
Gang, I have a question if such an animal exists, at least exist without the complication of a PLC, etc. The AHJ (USCG) s requiring that the fire pumps be outfitted with LVR controllers for obvious reasons. The existing plant uses LVP types but with additional remote start/stop from two...
We have three 37.5 kVA 480/120 single-phase transformers wired Delta-Wye to derive 208/120 at the secondary. At 37.5 kVA, the single-phase Voltage and Current at the primary is 480V x 78.125A. Configured in Delta, the Primary Line current is 1.732 x 78.125A = 135.3A - indicating a new kVA...
Here is a web string to Automation Direct showing their line of Miniature Circuit Breakers (MCBs)
https://www.automationdirect.com/adc/shopping/catalog/circuit_protection_-z-_fuses_-z-_disconnects/circuit_breakers_-a-_circuit_protectors/miniature_circuit_breakers_(mcb)#
Thanks
Thank you for the comments and questions. When I refer to miniature, I jump on the colloquial bandwagon these devices are often referred - these are the DIN Rail mount circuit breakers still falling under UL489. My application is for a critical motor control circuit where the motor itself is...
Thank you Mikel. I looked over the EGSA and there are elements that will help - Thanks. I will review the ISO ref.
The mission is as you say:
"looking at the electrical performance of the system, and trying to see if available utility service is adequate to power your site"
and
"do...
Thanks Gang, I have checked all the references identified above and it appears I have to construct my own based on bits and pieces of the foregoing. The closest I could find is the IEC 61000-4-30 - a standard governing power analyzer instruments themselves such as the Fluke 435 - covering...
Does anyone know of testing standards governing the testing of lv power distribution systems. I have an industrial system presently fed from a DG plant and need to evaluate performance to determine what is needed for a utility service option. So I will be testing things like motor inrush, pf...
Cost is not a great issue in that the alternative would be to run an overhead bus duct, and I would normally select to run an overhead bus duct in this case but for the heavy machinery traffic and vulnerability of the posts supporting the bus duct structure - ergo the subgrade approach.
The...
Gang, I have an application for a 50-meter 460 V cable run subgrade in ASSHTO class heavy grade precast concrete culvert with cast metal grate. The area is subject to periodic storm flooding to about 5 feet over grade. Many of the US cable manufacturers are telling me that their standard...
Thank you argotier. Yes, I concur, deriving is straight forward and thank you for your references - I will tag and archive. The Kennelly paper is priceless!
Thanks again
Jim