<-- Back Items 01 - 11

Item 12. Pole Pitch, t

Output	B"g	Output	B"g
5	37,000	750	61,000
10	42,000	1,000	62,000
100	53,000	4,000	65,000
200	56,500	5,000	65,500
300	57,500	7,500	66,500
400	58,500	1,000	67,000
500	59,000	Larger	67,500

For 60-hz machines running at moderate speeds, use Article 103, page 275 as trial value. Interpolate for corresponding HP/p. This value lies between 6 to 12 inches.
For final value, round-off trial value to the nearest multiple of 1/8".

Item 13. Gross Length of Stator, la
Use: la = D²la / D² = Item 09 / (Item 10)².
Round-off to nearest multiple of 1/8" without necessarily increasing the Output Factor, D²la.

Item 14. Dimensions of Vent Ducts, #v × lv × tv

v fpm	No. #v	width lv	thick tv
1,500	1	3/8"	1½ - 2"
3,000	1	1/2"	2 - 2½"
4,500	2	3/8"	2½ - 3"
6,000	2	1/2"	3 - 3¼"

Use the value nearest the calculated peripheral velocity, v above. For the thickness of the stack, tv, use the lower values for a difference in peripheral velocities of less than 500 fpm, else use the respective maximum.

Item 15. Net Length of Stator Core, ln
Use: ln = 0.9 × (la - #v × lv ).
Where #v is the number of ducts. Change this value when the motor temperature rise exceeds the limit.

IMPORTANT NOTE: For Item 16 to 19, make at least three (3) trial combinations in a table of values showing the trial n_s, l, C_s and q. Then select the most appropriate combination such that the final value of specific loading, q, is within the q_LO and q_HI, refer to Item 07. This combination would greatly affect the final values of the flux densities in the core, B"c, and teeth, B"t, as well as the slot dimensions and the ratio d/s.

Item 16. No. of Armature Slots per Pole per phase, n_s
Use: n_s is selected arbitrarily.
Possible numbers: 1, 2, 3, 4, 5, 6
For higher HP, this could reach up to 8, but this is not recommended because this would create smaller slot and teeth dimensions, thus the greater the probability that permissible values of flux densities would be exceeded.

Item 17. Slots per pole, S/p
Use: S/p = n_s × n.
Where n = 3 for three-phase machines.

Number of Armature Slots, S_A
Use: S_A = S/p × p.
Where p = the number of poles.

Items 18 - 26

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