Item 48a. Diameter of Rotor Core, D_H
Use: D_H = ½D + 0.25
Item 48b. Length of Rotor Bar, lb
Use: lb = la + 2l_R = la + ks
Where: 2l_R = ks accounts for the skewing the rotor bar one slot pitch and the distance between the ends of the rotor bar and the short-circuiting rings.
Item 48c. Resistance of Rotor Bar, Rb
Use: Rb = lb / ( CSb_final × ¼p × 10⁶) ohms.
Item 48d. Watts Lost in Rotor Bar, W_{B cu}
Use: W_{B cu}= S_R Ir Rb
Where: S_R = Number of Rotor Slots, see Item 40.

Item 49. Current in End Rings, Ie
Use: Ie = S_R Ir / p p
Where: S_R = Number of Rotor Slots, see Item 40.

Item 50. End Ring Current Density, De
Use: De = Ie / CSe = Ie / (m)_e
Standard is approximately 2 D_R = see Item 43.

Item 51. Dimensions of End Ring, CMe = CSe = (m)_e
Use: (m)_e in CM = CMe = Ie² × Re_total / W_{E cu} Cir. Mils.
Use: (m)_e in sq.in. = CSe = CMe × ¼p × 10^-6 sq. in.

Item 52a. Resistance of Each End Ring, Re
Use: Re = W_{E cu} / 2 Ie²
Item 52b. Mean Length per Turn of End Ring, (mlt)_e
Use: (mlt)_e = p ( lb - 3/4" )
Where 3/4" accounts for eccentricity.
Item 52c. Total Resistance of End Ring, Re_total
Use: Re_total = 2 (mlt)_e p
Where 2 accounts for two end rings, i.e., at both ends.
Item 52d. Total Copper Loss at End Ring, W_{E cu}
Use: W_{E cu} = W_{R cu} - W_{B cu}
Where W_{R cu} = Rotor Copper Loss
W_{B cu} = Watts lost at Rotor Bars.

Item 53. Total Watts Lost at Rotor, W_{R cu}
Use: W_{R cu} = s_trial ( 746 × HP ) / ( 1 - s_trial )
s_trial = s + 1%, where 1% account for full load conditions.
For the slip, s, refer to Art. 108, page 284. This is NOT the full load slip!
Round-off W_{R cu} to the nearest 100 to account for sundry losses.

Item 54a. Full Load Slip, s_FL
Use:

HP	Slip, %	f&w, %HP
10	4.0	2.5
30	3.6	1.8
100	3.2	1.2
200	3.0	1.0
250	2.9	0.9

s_FL = W_{R cu} / ( 746 HP + W_{R cu} ).
Item 54b. Slip Revolutions at Full Load, N_S
Use: N_S = s_FL × N

Item 55. Full Load Speed, N_FL
Use: N_FL = N - N_S = N ( 1 - s_FL )

Item 56. Calculated Efficiency, h
Use: h = 746 HP / ( 746 HP - SL_total )
Compare this to Item No. 04.
Use: SL_total = W_{A cu} + W_{R cu} + W_{A fe} + W_{R fe} + W_FW
Where:
W_{A cu} = Item No. 32
W_{R cu} = Item No. 53
W_{A fe} = Item No. 39
W_{R fe} = 0.05 W_{A fe}
W_FW = % f&w (746 HP). Interpolate for other values of HP.

Characteristics & Performance: Items 57 - 63

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