The features of the NW-25100:

• The typical dimensions of the basic system (HVAC control plus 480 volt and 120/208 volt circuit breaker panels) are 18 inches by 68 inches for most currently produced versions of this system if built in a vertical format. It is still possible for us to produce the older 62 inch high versions, but only with the loss of certain very desirable control system features or reduced number of 120 and 208 volt circuit breaker positions. Additional space for generator controls and/or DC system panels or other options will increate the height or width, depending on the shape of the space available.

• If the space dictates, it is possible to separate the circuit breaker part of the system and the HVAC control / DC control / generator control part of the system from the circuit breaker section of the panels. As an example, an RDC converted to a coach typically has a large electrical locker in the vestibule area and a very compact locker space accessible from the interior of the car. In most cases the HVAC controls would go into the interior locker area, along with generator controls and DC controls if desired.

• With electronically controlled systems, the HVAC status display (above, center example for a two zone system that has a separate display for each zone) may be a separate panel is a location that is separate from the HVAC power swtiches and circuit breakers.

• Amtrak and transit agency compliant HEP Main Breaker for 480 volt power coming from the head-end power system. Canadian compatible systems are able to have dual HEP system receiving but this consumes some additional height.

• Five 480 volt, three phase circuit breaker positions (Six including the HEP main breaker position). The typical unit also includes a 480v overhead heat breaker, 480v air conditioning condenser breaker, and a breaker for the 480v to 120/208v transformers.

• The programmable logic controller version of the NW-25100 has a number of options that may be programmed into the system. Options include adjustable floor heat level, error logging, and many other features. The main display menu for a typical example is shown above. Depending on the number of sensors and transducers installed on the car, it is possible to also display air conditioning refrigerant system pressures and other system status indicators that are able to help with system diagnosis and maintenance.

• Certain versions of NW-25100 have been equipped with a three-phase power monitor prevents damage to HVAC and other equipment by preventing operation when power supplied to passenger car has incorrect phase rotation or voltage imbalance.
  
• Certain versions have been built with a short-cycle timer to prevent the air conditioning compressor from starting until after a certain time, in order to meet the compressor manufacturer's specification to limit the compressor to a certain number of starts per hour. On most Northwest Rail Electric systems this is provided on the condener system, but if required to operate with a particular type of air conditioning system it may be added as an option.

• A 120/208 volt circuit breaker panel with 30 single phase circuit breaker positions is standard. Six breakers are provided in the standard package, but more may be included with the order if desired. The standard circuit breaker panel allows for 208 volt three phase, 208 volt single phase, and 120 volt single phase loads.

• Control for several HVAC stages, depending on the specific options desired:
  
  • Single stage air conditioning and three stages of heating, or two stages of air conditioning and two stages of heating are fairly typical, but various options may be added or removed depending on the requirements of the car.

  • It is fairly typical for the control system to take advantage of three blower speeds that are available in the typical Northwest Rail Electric evaporator unit but may be built for systems with single speed or two speed blowers.

  • Various options (below) may be added for additional control features.

  • Other HVAC stage configurations may be built to custom order

  • Current Temperature Display and Set Point Temperature Display

  • Indicator lighs provide system status indication.

  
  Typical NW-25100 Controls

• A typcial system is designed for a 480 volt 3 phase car supplied from standard North American HEP. However, 208 and 240 volt systems have been built for cars with other than standard electrical systems.

• 24 volt control voltage circuit breaker

• An emergency lighting circuit breaker and relay are normally provided for automatic operating of an emergency lighting system. The standard circuit is rated 20 amps at 12 volts or 13 amps at 28 volts, but this system may be customized to suit other needs or completely eliminated if emergency lighting is provided elsewhere.

• Several electrical terminal type options are available, with all terminals easily accessed after the control panel cover is opened. Terminals are a semi-closed type that are reasonably insulated against accidental touch of the high voltage parts (below, left). Cage clamp terminals (below, right) are standard on systems with programmable controllers due to space limitations and the number of connections that need to be made, as well as the ease of assembly for the customer.
  

• Custom-made engraved labels can be made to order for circuit breaker panels as well as other needs. The standard colors are black text on white (below, left), but various other colors (below, right) have been produced to meet various customer needs.
  

• Built-in 120 volt (or 480 volt, depending on the system requirements) to 24 volt transformer supplies all low voltage electrical equipment on the NW-25100, or it may be remte mounted with a connector if space requirements dictate a smaller system size. On systems with a programmable logic controller and display, low voltage power is provided by a 24 volt DC power supply that is part of the HVAC control and requires no additional space.

• All panel covers are powder coated (not painted) to provide a high-quality, long-lasting finish.

• Hinged cover over control components provides easy maintenance access to the interior of the panels.

Options:

• Additional Heat or Air Conditioning stages.

• Units with electronic controls may be equipped with presure sensors to allow the system to also display the refrigerant pressures in the HVAC system. This may be useful for system diagnosis and maintenance.
  

• Dehumidification is sometimes not desired and so it is provided as an option. In some units, dehumidification control has been moved to the interior of the enclosure to prevent accidental adjustment of dehumidification rather than the temperature control. Note this is shown in the photograph at right - the humidity control is the blue box located inside the control panel enclosure. In other cases it may be mounted in a recessed location on the panel cover, as seen in the system pictured at the top on the left. In programmable logic control versions dehumidifcation is mostly a difference in programming with a combined humidity and temperature sensor.

• Proportional heat control. This is easiest on the versions with electronic control, but is also a possibility on certain other versions. This allows the heat to adjust to the level required to maintain the temperature in the car so that there isn't as much temperature fluctuation as is the case with heat stages turning on and off.

• Indication or controls in a location other than the main electrical locker. On electronically controlled units this frequently means the display unit is located in a different location than the main HVAC power contactors and switches. On other systems this sometimes means the temperature controls are separated from the rest of the system, but it all depends on the customer needs.

• Remote data reporting: on certain systems it is possible to use a cellular modem or other wireless network connection to provide system data and some control.

• Additional independent control of floor heat / baseboard heat, if no additional stages of heat or air conditioning are added. This is sometimes useful in cars with freeze protection, bedrooms or other area where a separate heat zone is useful.

• If being used with a system other than a Northwest Rail Electric NW-BEOH-C, may be ordered with single speed blowers or otherwise modified to suit the existing evaporator and condenser.

• Generator Control

• DC Control

• Package size or shape changes to adjust for space available, as seen here:
  
  A modified NW-25100 package with the breaker panel
  beside the HVAC control unit, and a
  generator control panel added under the HVAC control.

We also have a two-zone version NW-25200 available, for dome cars or other situations where two control zones are desirable.

The NW-25100 may also be incorporated into custom control panels and complete locker packages of various types. See our Custom Locker Packages for some examples of custom packages that use these as part of a larger custom package, as well as other custom electrical packages for railroad passenger cars.