3 Benefits of Using 4-20mA Signal Splitters

Signal splitters are one of the most commonly used devices in process automation and control. They are used to split an incoming signal into two or more outgoing signals, each with its characteristics.
There are many benefits of using 4-20mA signal splitters, but let’s focus on three of the most important ones.

In the simplest 4-20mA loop, there is a transmitter and panel indicator with a built-in 24 Vdc power supply for the loop. More difficult loops could contain a 4-20mA transmitter, a 24 Vdc power supply, a panel meter, a PLC, and a recorder.
If a power supply in the field powers the transmitter, you could have a different ground. It is possible to end up with ground loops that could cause problems on this loop and to the PLC or recorder as a whole.
The advantage of an isolated 4-20mA signal splitter would be that input and output would be isolated from each other. Another problem that may only become apparent after some time is that the insulation on one component could break down, maybe from a lightning strike or corrosion.
This problem could be challenging to find and eventually solve. Installing 4-20mA signal splitters should be the standard to prevent ground loop problems.

The impedance of several control room devices and the cable length may be too high for the 4-20mA loop. It is possible that the problem only becomes apparent when the signal approaches 18 to 20 mA.
I have seen the output of a transmitter being 20mA when checked with a multimeter without the loop. But when I reinstalled the loop, I’d find that the loop had dropped down to 18mA with the multimeter and the control room devices being in series. Introducing a 4-20mA signal spitter can boost the output of each circle and give each control room device its loop.
Corrosion on the terminals, especially in the field of a chemical plant, could appear after some time and be enough to increase the impedance and limit the 4-20mA, which could be drastic. Installing 4-20mA signal splitters can help prevent high impedance problems.

Should an installation involve a signal transmitter and many control room devices, the wiring could be some distance due to a loop. A problem with any part of the loop or an instrument will bring the whole loop down.
With the introduction of a 4-20mA signal splitter, the output loop will become independent from the other loop and the input. Each control room device will have its loop, which will not affect the other loop.

Installing 4-20mA signal splitters should be the standard installation today to prevent loop failures and bring down the whole loop tomorrow.
Installing a 4-20mA signal splitter should be the standard in process automation and control to allow isolation, boost the range, and improve reliability. It will help prevent problems that may only become apparent after some time and could be challenging to solve.