Custom Heating System Design Puts Locomotive Engine Preheating On-Track

Circulation Heater

The Challenge
Chromalox helped this transportation industry customer solve an unusual heating system design challenge. A heated water/glycol mixture is used to preheat the engines of the customer's locomotives. The power source for the heater used to heat the mixture is the engine itself, which drives a variable frequency drive. The locomotive has several gears and operates over a range of RPMs, which means that the supply voltage to the heater varies from 184V to 552V. Because no standard heater design or control system is capable of handling such a large variance in supply voltage, a custom solution would be needed.

The Solution
Our local Chromalox sales engineer worked with the customer to customize a circulation heater and temperature control system for this unusual engine preheating application. The solution begins with a Chromalox Water/Glycol Circulation Heater designed with six heating elements that can be wired electronically in up to six unique three-phase circuits. The control scheme monitors the locomotives gear and engine speed. Depending on these parameters, a series of switches are electronically opened and closed, effectively wiring the heater for the appropriate supply voltage. In addition, an SSR Power Controller is used in the control system to regulate the power supply.
The customer realized significant value working with Chromalox to design a highly customized solution. The customers schedule was tight, but Chromalox worked with the customer to develop a build schedule that met their needs. In addition, having a local Chromalox sales engineer who was able to visit the customers site and review the specific application helped speed the process and contributed to a successful result.