What Do SCR Clamps Do and Why Are They Important?

A scr clamp from the OEM series floating on a white backgroundIf you are buying and/or installing an SCR device, then the chances are that the clamps you will use to hold the device together are probably an afterthought. You are probably focused on what you need the device to do and what type to buy and install. What type of SCR clamps to use may seem like a minor problem that is not worthy of much thought or concern. After all, SCR clamps are just a minor accessory, not a main component of the device. Or, are they?
Once you really understand how SCR devices work and what the clamps really do, then you get a new sense of how important SCR clamps really are, how important it is to pick the right one, and to make sure that it is properly calibrated to apply just the right amount of pressure. Pick the wrong clamp, calibrate them ineffectively, or apply too much or too little pressure, and you could cause big problems. They may seem like a relatively unimportant detail, but in reality having the proper clamp and making sure that they are calibrated correctly is essential to the long, trouble-free life of the device.

Types of SCR Devices

SCR devices come in two main types. First, there are module – type SCR devices, featuring anywhere from 2 to 6 SCR’s lined up together. Then, there is the so-called Hockey Puk SCR device, so named because it resembles a traditional hockey puck. These two different types of SCR devices are designed differently, but they have one important feature in common. They each have at least one heatsink, which is designed to absorb excess heat and then transmit it through the base of the SCR device, in order to keep the device from overheating and thus failing prematurely.

Consider These Installation Factors to Prevent ProblemsWoman in a white blouse hold an SCR Clamp she is facing the camera and smiling, she has long dark curly hair

The electrical conductors are either small machined threaded inserts, or thin bus bars. Either way, they must have the proper torque in order to ensure proper power flow. A connection that is too loose, will cause the connection point to overheat and will lead to premature failure. If the connection is too tight, it can stress the module internally and cause failure. Therefore it is extremely important to get the torque right, for both the electrical connections and the base mounting.

Hockey Puk SCRs

With Hockey Puk SCRs, the base transmits both heat and electricity and so it is even more important to mount, center and seal the base properly. All services should be touching perfectly and the pole faces should be parallel to each other, so that both the heat and electricity will travel from one complete surface, to the next complete surface. The higher the power rating for the device, the greater the mounting force required.

There are two main types of clamps available for Hockey Puk SCR devices. Some have spring gauges and the more popular type have stacks of Belleville springs, which pre-calibrate the amount of torque needed. The clamping force is then established when the free calibration indicator is loose. This eliminates the need for torque wrenches and other tools.

Choosing the proper SCR clamps, particularly for Hockey Puk SCRs, will ensure that your device runs properly and avoid premature failure due to excess heat build up.