Interpretation Red Book IEEE Sdt 141
Interpretation Red Book IEEE Sdt 141
(OP)
I need help for the selection from a circuit breaker to 4.16 KV.
For the momentary duty, I calculated the first-cycle network, using a estimated first-cycle reactance of 0.17 pu for motors at 4.16KV, 350HP; a estimated first cycle reactance of 20 pu for motors to 480V, 75 HP and 60 HP.
For the interrupting duty I calculated the interrupting network, using a estimated interrupting reactance of (0.17 X 1.5) pu for motors at 4.16KV, 350 HP; a estimated interrupting reactance of 0.50 pu for motors at 480V, 75HP and 60HP. Standard interpretation Is correct?
For the momentary duty, I calculated the first-cycle network, using a estimated first-cycle reactance of 0.17 pu for motors at 4.16KV, 350HP; a estimated first cycle reactance of 20 pu for motors to 480V, 75 HP and 60 HP.
For the interrupting duty I calculated the interrupting network, using a estimated interrupting reactance of (0.17 X 1.5) pu for motors at 4.16KV, 350 HP; a estimated interrupting reactance of 0.50 pu for motors at 480V, 75HP and 60HP. Standard interpretation Is correct?






RE: Interpretation Red Book IEEE Sdt 141
Alan
----
"It's always fun to do the impossible." - Walt Disney
RE: Interpretation Red Book IEEE Sdt 141
The base is motor rating.
For 20 pu in momentary, Table 4-2, column "first cycle network", line "all others, 50 HP and above" 1.2Xd" or estimated the first cycle network X=0.20 pu based on motor rating.
For 50 pu in interrupting, Table 4-2 column "interrupting network", line "all others, 50HP and above" 3.0X" or estimate the interrupting network x=0.50 pu based on motor rating
All motors, the nameplate reactances are missing.
Is correct?
RE: Interpretation Red Book IEEE Sdt 141
Alan
----
"It's always fun to do the impossible." - Walt Disney
RE: Interpretation Red Book IEEE Sdt 141
Is correct, 0.20 pu and 0.50 pu according to Table 4-2 foor notes, IEEE std 141-1993.
Pardon went an error when writing the reactance.
RE: Interpretation Red Book IEEE Sdt 141
Does that answer your question?
Alan
----
"It's always fun to do the impossible." - Walt Disney
RE: Interpretation Red Book IEEE Sdt 141
For medium voltage motor (350 HP), the nameplate are missing, thens estimated reactance for first cycle is 0.17 pu (at 150 KVA base, 1 KVA = 1 HP), the estimated reactance for interrupting network (0.17 X 1.5)?
Applying Table 4A1, Line "Individual large inductions motors, usually above 600 V": Xd"=0.17 pu of machine KVA ratings