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Re: Series-mode surge protection

 

I am not a fan of the SurgeX units.? I have seen little evidence that they do what they claim and there are some serious design flaws for such an expensive unit.? An example would be the obvious one - a ground bonding point.? They don't have one and rely solely on the power safety ground connection which does not provide a good bond for bonding purposes.

You would be much better off installing a Type 2A SPD with SADs and MOVs in replaceable modules at your electric panel plus a Type 3 SPD PDU at your equipment.? This combination takes care of the vast majority of spikes and surges effectively and they do not blow unless there is a very significant incident.? This is the combination specified for communications sites in Motorola R56 and thousands of mission-critical communications sites use this configuration effectively.? I would trust that any day over a snake-oil solution.

Dan Woodie, CETsr
KC8ZUM

On Sat, Nov 19, 2022, 10:08 AM <rsnyder@...> wrote:
I recently installed?series-mode surge protection devices (SurgeX SX-1115-RT) on two repeaters that have switched-mode power supplies.? The surge protectors do not use sacrificial components such as Metal Oxide Varistors (MOVs) that are commonly used in low-cost units.??They are designed to withstand up to 1000 occurrences of surge pulse voltages up to 6000 volts, or 500,000 occurrences of 1000 volts.

I don't have any way to monitor line voltage surges or spikes, so I can't tell whether the devices are actually doing anything on a day-to-day basis.

I have two theories:

1. Occasional, small voltage spikes can gradually weaken semiconductors such as MOSFETs used in switching supplies.
2. Large voltage spikes?are most likely to occur at precisely the time when the repeaters are most needed, i.e. during some type of disaster.

The series-mode surge protectors appeal to me because they protect the equipment from a virtually unlimited number of small surges on a day-to-day basis while also handling occasional large spikes without without requiring a human to visit the site to replace a self-sacrificing surge protector.

I am whether anyone else has experience using series-mode surge protection devices at repeater sites.? Are there any downsides to these devices?? For example, are the devices prone to failure due to age, heat, moisture, dust, or vermin?

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