800 Amp Stainless Steel Wayside Power System with Twin Horizontal Controls400 Amp Wayside Power System with Vertical Controls
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Wayside HEP Power Systems

From Northwest Rail Electric

Phone: (503) 231-4808, Fax: (503) 230-0572, E-mail

See where our equipment is located on a typical railway passenger car

Wayside power systems are designed to feed 480 volt, three phase power from the electric utility to the train through the HEP system or a dedicated "yard power" connector. These systems have been referred to as "Yard Power Units", "Wayside Power Units", "Wayside Power Systems", "Wayside Power Panels", "Shop Power", "Ground Power" or a number of similar terms. Providing standard utility power to the train for maintenance or layover is far cheaper (and quieter) than running on-car generator sets or providing HEP power from a locomotive. In enclosed car shops there is no ability to run the on-car generators anyway due to the exhaust. Northwest Rail Electric wayside power systems are the NW-YPHP series of model numbers, with the various letters and numbers following indicating the capacity and various custom options. Customers using Northwest Rail Electric NW-YPHP systems range from small car storage and maintenance operators to railroad museums, tourist railroads, commuter operators and intercity passenger train operators.

Front of 200 amp yard power unit
The basic package (a 200 amp package for maintenance shop use is shown at right) provides fairly simple operation, while more complex packages (as seen in the controls below) are designed to meet a number of different specifications and needs of various commuter railroad and long disantce passenger carriers.

Typcial labels of a NW-YPHP Wayside Power System
Typical controls and their labels on a more complex NW-YPHP yard power system. Note
that this system features a control power keyswitch with a padlockable transparent
cover so that even when padlocked it is possible to see the position of the locked switch.

All versions of the YPHP are equipped with a three phase power monitor that will shut off the power feed in the event of phase imbalance, or improper phase rotation. As required to safely operate any HEP system, all systems are also equipped with a trainline control loop safety.


Frequently, more sophisticated functions than simple power feed start and stop are required in wayside power systems. In such cases various features may be added, and listed below are only a few of the options that have been built into various wayside power units made by Northwest Rail Electric over the years:

Points to Consider:

Custom Variations:

We have built quite a number of custom variations over the years. For more information see our Custom Yard Power Units page for a few examples.

These systems are a vital part of maintaining and operating railroad passenger equipment, and virtually any needed or desired feature may be provided. Northwest Rail Electric can help you determine what features are desirable, from extremely simple systems such as shown at the top of this page to the more complex and custom systems.


We are able to provide a number of different extension cables for connecting the train to the system as well. Contact us to determine pricing for the particular cable length that you require.

Related Products from Northwest Rail Electric:

For those doing a complete upgrade on a railroad passenger car, we also offer:

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