by Bob Bob
I/O-24 surge protector
I/O-24 Surge Protector

The ZeroDT I/O-24 is a surge protector that’s unlike any other. This I-O protective device stacks up very differently when compared to other surge protection devices, and offers a wide range of advantages. Let’s dive into a few.

Comparing SD32 and SD32X Devices with the ZeroDT I/O-24

A few of the more well-known surge protectors include the MTL SD32 and the Weidmuller SD32X devices. Both of these are industry-leading surge protectors that can effectively assist in protecting customers’ devices from overvoltage transients and surge currents and ensuring that electronics can continue to function the way they were built.

In contrast, the ZeroDT I/O-24 is a newer surge protector that uses a different technology to protect electronics from these overvoltage transients and surge current issues. At ZeroDT, we’ve created an advanced surge protection device that offers you all the capability you’re looking for and that truly is a step up from the SD32 and SD32X. Learn more about ZeroDT with our comparison.

Pros and Cons of the SD32 and SD32X Protectors

One of the main advantages of the SD32 devices is that they offer a fused disconnect. By removing this disconnect, the user has the ability to isolate the circuitry without an additional disconnect switch. However, there is no fuse disconnect capability on the SD32X, meaning that this doesn’t apply to all of the SD devices.

Both the SD32 and the SD32X offer a third connection on each unit for the cable shield. While this can offer a place to ground the cable shield, if you connect the shield to this terminal, it grounds the shield of the cable at that point which may not be the optimum point for effective shielding and in fact may introduce currents onto the shield if other ground points are used as well.

The SD32 units are designed to protect only a single loop or 2 wires, and it takes up 7 mm of DIN rail space. It must be installed in the correct orientation in order for it to function as a surge protector. It needs to be installed with the GDT towards the side that the surge comes from (typically toward the field device in a cabinet/panel application). What’s more, these GDT systems degrade over time with usage, which can lead to frequent and costly replacements.

An Overview of the ZeroDT IO-24

Unlike the SD32 units, a ZeroDT I/O-24 only takes up 12.5 mm of DIN rail space and protects two pairs or 4-wires. Using two of the SD32s to protect two pairs takes up 14 mm of DIN rail space. That’s a whopping 17% more space!

Another way that the ZeroDT I/O-24 differs from the SD32 units is that it is fully bidirectional and can be installed without worry as to the correct orientation. It’s not important for one side of the unit or the other to be facing the side of the surge, giving you more flexibility with installation and eliminating installation issues. Similarly, in the advent that there is a surge or transient that originates on the cabinet/panel side, the I/O-24’s bidirectional capabilities prevent that energy from going out to the remote field devices and causing damage.

On top of that, the ZeroDT I/O-24 uses only SASDs to provide protection that does not degrade with usage. The GDT component within the SD32 degrades every time it handles a surge and the arc lights. With the I/O-24, you are still getting the same level of protection five years down the road as you did the day it was installed.

Similarly, the non-degrading ZeroDT never gives you a unit that is partially functioning, you either have a unit that has 100% capability, or the unit has ‘self-sacrificed’ and is shorting the line to the ground so that you know that there is an issue with that circuit.

Finally, there is no need for high bandwidth versions of the ZeroDT I/O-24 as it does not interfere with digital communications like the RS232, RS422, and RS485. The I/O-24 can be used with confidence on everything from analog 4-20 mA loops, to digital communications loops carrying CAN bus, HART protocol and Profibus — to DC power loops for other devices. Each of the 4 lines through the units has its own independent surge protection so you can trust ZeroDT with protecting your equipment.