Graphing motor amps is a simple and inexpensive method of conveyor condition monitoring. Over time, you will gain insights into the effects of lubrication, wear, tension, alignment and overloading on the overall health of your conveyor, so you can take steps to better maintain it.
Efficiency is the watchword for many businesses, but especially in the conveying industry. Efficient conveyors move more material, consume less energy, and maintain good health for longer – which equates to increased productivity and profitability.
But how do you tell if your chain conveyor is running at optimum efficiency?
The key is to measure and monitor the motor amps.
The amp value represents the energy drawn by the motor and, therefore, the amount of ‘work’ it is doing.
If you have a PLC (programmable logic controller) integrated in your conveyor system, this will give you an amp reading. Otherwise, you can use an amp clamp (clamp meter). These are widely available online or from electrical trade suppliers.
First, establish a baseline by noting the amp value when the conveyor is running empty. Then add product to the conveyor to discover the upper limit. When the conveyor is loaded, the work required increases and, therefore, so do the amps needed by the motor to drive it.
Graphing the amps used over time will give you a picture of how the conveyor operates under different conditions and the health of the system. If the amps start to increase, it may mean that you need to lubricate the chain, for example.
Some PLC-controlled conveyor chain systems will automatically monitor amps and use the data to set an upper limit that trips the motor when reached to prevent damage to the chain. Others may use the amps being drawn to set off a lubrication cycle.
Discovering the root cause
If the chain is well lubricated and the amps still increase over time, then it’s a sign you need to investigate in further detail.
The chain lubricant might no longer be effective because it’s not getting to the pin and bush cavity; the chain tension might not be applied correctly, increasing the work the conveyor must do; or perhaps the chain is coming to the end of its life, causing friction between the components to increase.
In any case, measuring motor amps is a really simple and inexpensive method of conveyor condition monitoring. The insight it provides will save any chain conveyor operator both time and money.
Safety note: Before carrying out any electrical work on your conveyor, ensure you have completed the appropriate risk assessments and method statements. Electricity is unforgiving and its sentence deadly, instantaneous and without an appeal.