Model 15 Gear Sets

Set	Gear	Teeth		Pinion	Teeth	OPM	WPM	Motor
80437	74913	30		74912	7	368	60	60 Hz Sync
96535	91287	24		91286	7	460	75	60 Hz Sync

84042	84019	25		84018	7	368	60	50 Hz Sync
107474	107460	20		107461	7	460	75	50 Hz Sync

84042	84019	25		84018	7	368	60	25 Hz Sync
107474	107460	20		106461	7	460	75	25 Hz Sync

80374	74151	35		74505	7	368	60	110 AC Series
96536	84106	32		84105	8	460	75	110 AC Series

80374	74151	35		74505	7	368	60	110 DC Shunt
96536	84106	32		84015	8	460	75	110 DC Shunt

80374	74151	35		74505	7	368	60	220 DC Shunt
96536	84106	32		84105	8	460	75	220 DC Shunt

All governed motors used an 87.6 vps tuning fork for the speeds indicated.
Note use of same gear set for 25 and 50 Hz sync motors, which means that
the 50 Hz motor is four-pole and the 25 Hz motor is two pole, so they
run at the same speed, 1500 RPM.   The governed motors all run at 2100 
RPM.