Phoenix Uno Power Supply Failures

[edd189]

At my company, we are seeing massive failures of the Phoenix Uno power supply. This is a small 400-500v input and 24VDC output power supply. We connect it at 480V.

Within an installed base somewhere around 20,000 units, I would estimate we have had somewhere around 500 fail after being in service approximately 2-3 years. This seems low on the surface, but the failure rate is still well above the manufacturer's rated MTBF.

The issue internally is always a blown MOV.

Is anyone else using this unit? Are you experiencing failures?

 

[A_G]

Welcome to the forum! My understanding,MOV varistor is for surge protection. If it keeps on failing maybe your incoming power is dirty. It has been a while since I dealt with this kind of issue. I remember it is more common in some countries abroad such as India as opposed to the US. Ideas for improving power quality can be a noise filter of some kind or an isolation transformer

 

[Jarnosa]

Have you spoke with your local Phoenix Contact technical support?


How much you take current out from power supply? If you have some kind of current peak in 24V side, try to change bigger current supply (t.ex Trio 5A, 2903153)



I have used Phoenix Contact power supplies about 10 years(Uno, Trio, Quint) and I have seen old working Phoenix contact power supplies from 90s. I have changed 0 Phoenix contact power supply. Most of the problems i have got with Murr and Schneider.