Why did they go from Series to shunt motors

[chuckinnc]

I farm and have 3 carts, 99 ezgo series, ezgo dcs and yamaha g19 also shunt type. Both shunt types have had their share of problems while the older series cart keeps on going. Other than smaller field wiring and maybe less field current what would be the reason to change to more fragile problem prone drive system from a proven (almost) trouble free series system

[JohnnieB]

Originally Posted by chuckinnc

I farm and have 3 carts, 99 ezgo series, ezgo dcs and yamaha g19 also shunt type. Both shunt types have had their share of problems while the older series cart keeps on going. Other than smaller field wiring and maybe less field current what would be the reason to change to more fragile problem prone drive system from a proven (almost) trouble free series system

I don't know about the G19, but the stock DCS controller (Curtis 1206SX) was EZGO's first attempt at a sepex drive and was problematic, to say the least, so it was only produced 1995 thru 1999. Subsequent designs (PDS and TXT-48 ) are far more reliable and the aftermarket Alltrax XCT sepex controller is far more versatile as well as more reliable then the stock Curtis controllers used (1206MX and 1206HB respectively).

Sepex drives (shunt motor) are inherently faster and slow less going uphill than series drives. On the other hand, series drives have more low end torque, so if you carry heavy loads, or pull stuff and travel at low speeds, a series drive may be the better choice, but I've heard of a PDS (upgraded controller, solenoid and cables) cart being used to pull a manure spreader.

[kernal]

Here's a guess. Golf cart companies have bean counters, lawyers (product liability) and have to deal with Fed regulations. The primary reason to build golf carts is still for--golf. Other uses are secondary so far. Series carts are at the will of gravity if a drunk golfer falls off or cart barn boys want to push them into the water hazard. Shunt wound carts offer walk away protection and top speed limits to comply with Federal regs. (nanny state). EZGO quit series carts about 2008 and 36v carts by early 2010. CC and Yamaha are similar. As of this year Yamaha has quit DC motors on electric carts altogether in favor of AC motors. EZGO is mostly AC motored and CC is coming along. Probably other reasons I haven't thought about.

[cgtech]

Everything yamaha G19 & newer (1996) were all 48v & sepex.