This is a guide to the quality and performance differences of a generic surge protector strip versus a proper line protection device.

Most off the shelf surge protectors are not suitable for use with our machines, even the expensive multimedia ones.

Thunder Laser USA does not typically recommend the use of plug strips or any other line protection, conditioning, and backup devices with Thunder Laser equipment. 

Ordinary “Surge Protectors” offer limited, if any, protection from lightning suppression.  These types of devices not only lack adequate noise filters, they can create more noise and high resistance connections in the line and this noise can adversely affect the operation of your equipment. 

The vast majority of these plug strips are not rated for 20A @110VAC, but rather 15A @110VAC. They also typically have low quality 15A @100VAC thermal breakers which will not satisfactorily supply power to your laser. 

This is the inside of a typical plug strip "surge protector". It has 3 Metal Oxide Varistors (the blue things) for overvoltage clamping, arranged in single phase, line to line, and line to ground configuration so they do help mitigate spikes and transients. There is also a capacitor for arc suppression and also as a decoupler to filter common-mode noise.

Additionally, leakage current is created when using MOVs between line to ground and line to neutral (most main panels have the ground and neutral bus bridged) and when using a cap across the same for filtering so look for the UL certification as they test the devices for leakage current and will fail the product if it exceeds 0.5 mA.

If you must add a surge protector look for one similar to this:

This is a SmartPower SS-15 TN. NOTE: This is a 15A 110VAC model. There are 20A model from SmartPower and others. These are made for copiers which are far less tolerant of line conditions and employ similar mechatronics.

This model has 8 MOVs and a host of chokes and filters as well as a watchdog circuit that will indicate proper operation as well as shut down the devices if line conditions are not within spec. Some models use a differential transformer and caps for low pass, common-mode, and normal-mode filtration.

Here is a similar 20A model on Amazon: https://www.amazon.com/ESP-Digital-Surge-Protector-Filter/dp/B00KHP3K8C/