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In 2005, when Marshall and Janet Tuttle bought Donner Ski Ranch, they sought to improve guest services while controlling costs. The Tuttles took a hard look at the entire facility, starting with the lifts. And since they were not lift experts themselves, they hired Truckee-based JMF Electrical Constructors Inc. to do a complete electrical inspection.

The contractor provided a report outlining the baseline condition of the equipment and organized the relevant technical documentation. The contractor also provided a schedule of required and recommended repairs, as well as a comprehensive, preventative maintenance schedule and corresponding program.

Then the Tuttles did something really different: they hired JMF to be their maintenance team.


The “Before”
Donner Ski Ranch, or “the Ranch” as locals call it, is a small family-owned and -operated resort that caters to families and beginners. Started in 1937, the resort encompasses roughly 500 acres and serves about 65,000 skiers and snowboarders per season.

Donner operates six lifts. Chair 1, a fixed-grip Poma, was powered by an out-of-support, temperamental Fincor non-regenerative DC drive. Chairs 2, 3, 4, and 5 were fixed-grip Riblet doubles with wound-rotor motors, drum controllers and 12-volt DC control systems. Chair 6, also a Riblet double, had an equally out-of-support Avtec non-regenerative DC drive and control system.

All the lifts suffered from years of operation with little or no electrical maintenance; countless technicians with varying levels of experience and competence working on the equipment; and poor wiring and repair practices. The equipment was outdated and largely unsupported, and replacement parts were difficult and expensive to acquire.

Day-to-day issues were nearly impossible to troubleshoot as there was no documentation, and the electrical panels were literally “balls of wire” connected with wire nuts and masking tape. It was commonplace for the lifts to mysteriously stop and “just start working again.”


Biting the Bullet
While many small companies might have asked, “How can we afford to fix all this?” Marshall Tuttle asked, “How can we afford not to fix this? Reliable and consistent lift operation is one of the cornerstones of a good reputation in the ski industry.”

Working with the lift contractor, Tuttle completed a cost-benefit analysis. The equipment, material and labor budget for the entire project came to about $200,000. Still, the goal of keeping the Ranch’s lifts operational and compliant with today’s standards could be accomplished at a fraction of the cost of new lift construction—particularly when associated permitting issues and environmental impact were considered.

Donner settled on a three-year timeline to stretch out the costs. A solid team of engineers and technicians was assembled. Superior Tramway of Spokane, Wash., served as the lift design and certifying entity, providing a low voltage control system and professional engineering services. Amptech Solutions, a San Francisco Bay Area-based consulting and service firm, provided the new regenerative DC drive systems, motors and associated engineering services.


The Ranch Is Retro(fit)
The Ranch has realized numerous advantages from this upgrade. Most critically, lift safety is vastly improved. The new electrical systems perform to the latest codes and include multiple safety circuits to ensure the lifts operate as designed. The safety circuits can be tested by an on-site technician with minimal experience at the “push of a button,” and fault annunciation is clear and precise.

Further, the lifts operate more effectively and efficiently. Lift speed regulation for the old wound-rotor systems was very poor—speed fluctuated with load, temperature and supply voltage variances. The new drive systems have a speed regulation of .04 percent regardless of these variables. The new drive systems also allow for infinite speed control, whereas the wound-rotor system could only provide a few step changes in speed. The slowest speed for a wound-rotor system, only about 50 percent, can be problematic for beginner lifts. So an investment in greater speed control made the Ranch more user-friendly for families and beginners.

Electrical efficiency is also dramatically improved. At an average lift speed of 70 percent, the wound-rotor efficiency was approximately 60 percent compared to approximately 84 percent for the DC system.

Further, in 2006 the local utility, Pacific Gas & Electric (PG&E), began an Energy Efficiency Incentive Program. Among the offerings was a program for “Non Residential Retro-fits.” Energy-efficient technologies were eligible for cash rebates of $0.08/kWh.

PG&E was able to provide the electric use data for the years 2004 and 2005, the seasons before and after the retrofit of Chair 2. In the season prior to the retrofit, electric usage was 12,288 kWh; afterward, it was 9,883 kWh, a reduction of 20 percent. Chairs 3 and 4, which were also converted from wound rotor to DC drives, will see similar savings. All told, Donner Ski Ranch should see an overall load reduction of more than 20 percent.

The braking system was improved by using the regenerative capabilities of the new drive to stop the lift, leaving the service brake only to hold the lift once stopped. This makes for more consistent stops with less wear on the service brake. In addition, a torque proof system allows the brake to “see” proof of torque from the motor before releasing. This helps prevent the load from rolling back onto the mechanical backstop.

Greater reliability is another benefit of the electrical upgrade. Replacement of electro-mechanical devices with solid state devices significantly lengthens component lifespan. The advanced motor protection features of the drive systems reduce various types of motor failure by alerting the technician to developing problems. Programming within the digital drive replaces numerous old analog circuit boards, which reduces spare-parts inventories. In addition, digital circuitry does not suffer tolerance drift with age and temperature like analog circuitry can, thereby maintaining consistent operation for years to come.

From the technician’s point of view, when every lift is well documented and identically wired, routine maintenance and troubleshooting are far less time-consuming and spare-parts inventories much easier to manage, resulting in less down time. Further, the technician can easily monitor and manipulate the system through a password-protected display that provides complete system information in plain English and standard units. When all the controls are identical, regardless of the lift, it is much easier to train the operators—especially when they hail from various regional and language backgrounds.

Summers 2005 and 2006 saw Chairs 1, 2, 4, 5 and 6 receive new drives, low voltage controls, comlines and operator stations. Chair 3 is getting its complete electrical retrofit this summer.

The remaining question was whether to perform preventative maintenance in house or contract it out. To keep it in-house, Donner Ski Ranch needed to 1) purchase all the tools and materials necessary to safely and properly do the work, and 2) find someone qualified to do the maintenance.

In the end, the industry shortage of well-qualified electro/mechanical technicians led Donner to contract out the maintenance and troubleshooting, at an annual cost of about $10,000 to $12,000. That includes all lift electrical troubleshooting and repair services throughout the winter, electrical maintenance on all the lifts and related comlines and controls. Essentially, The Ranch secured the services of an in-house electrician; after calculating full in-house costs, including wages, taxes, workers comp, etc., and liability, this was the most economical solution.


The “After”
Each of the five overhauled lifts has operated approximately 2,400 hours during the past two seasons, with no major electrical casualties or “mystery stops.” Minor issues were diagnosed and repaired quickly. The uniformity of the control stations has allowed operators to move seamlessly from lift to lift.

In other words, the mountain has never run more smoothly.



John Fehrman (john@jmfelectricinc.com) is president of JMF Electrical Constructors Inc. Michael Stuart (mjstuart@sbcglobal.net) is president of Amptech Solutions, which specializes in drive and control systems.