Are phase inbalance and ground essentially the same thing? ie: does phase inbalance imply that there is a gnd fault somewhere? or are they totally independent?
Manufacturer/Model:
THERMAL O/L & STALLING RELAY
P&B GOULDS
Mn 5ALI-C53-5
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example:
tap - 74A (FLC of motor)
ct ratio - 100:5
time: curve 1 or 4
% overload - 1.05 * FLC
is the current tap setting = 1.05*(74A)*(5/100)?
I have a bunch of data for various thermal o/l and stalling relays. can anyone tell me what it all means?
tap:(this is the current tap setting i'm assuming)
time setting: stall:45 (what does this mean? is this just the time setting on the relay like any other relay that goes along w/ the...
yes, but unfortunately i'm not designing a sys. w/ these relays (they're obsolete)...i'm modeling a power system in software that has these relays (using etap). etap does not have the model for the relays in there and i am unable to find the data (tcc curves) for the relays.
I'm looking for the time current curves for various P&B Golds THERMAL O/L & STALLING RELAYS. Any help in finding this information would be greatly appreciated!
I've tried their website (http://www.pbeng.co.uk/) and even contacting them but with no luck.
thanks...yes i'm just looking for typical values. do you mind me asking where you got this data from? (just curious for future reference and so that I can back up any information that I use).
"sometimes a lower fault current provides a worse arc flash hazard than a higher fault current" - Can you elaborate on this? In what instances would this occur?
Yes. I'm mainly looking for very general motor characteristics. I do not have information about each and every motor. ie: General PF, Effy, and X/R ratios for induction motors with a certian HP and voltage rating, that type of thing.
Looking for a reference on fuse sizes and fuse characteristics? ie: what does 200E or 45R mean? Does this describe the tcc, interrupting rating and continuous rating, voltage rating...etc?
I am currently developing a list of fault scenarios for an arc flash study with a system containing over 500 busses and am wondering what the standard for developing these scenarios is? ie: Do I consider a fault at each and every bus for each operating configuration (tie breakers closed, tied...
Does anyone know of a reputable source for induction motor characteristics such as common efficiency and power factor values? I know that the ieee colored books (the red one on protection i think...) has some information on this - unfortunately I do not have access to these books? Suggestions...
I am currently developing a power system model using ETAP software (http://www.etap.com/), and need to model various P&B Golds relays. Unfortunately the ETAP software does not have the P&B Golds relay model built into the software. Are the any current P&B Engineering Relays that have similar...
