What is Current Sag/Swell and its application?

[Arneil_Dalope]

Hi,

I would like to know the reason why the PM8000 and ION7400 have Current Sag/Swell and more important what is the relation of this to Power Quality, if there is any, so we can explain clearly to our customers.

Unlike Voltage, which we expect to have a nominal steady value depends on what the supply is, the current obviously varies.

We understand how the framework works but would appreciate if someone can explain why have this and where can we apply this feature.

Thanks.

[DanL]

The PM8000 and ION7400 inherited this feature from the PM870. see "Chapter 9—Disturbance Monitoring (PM870)".

Unfortunately, the PM870 documentation only details the consequences of voltage disturbances, and merely mentions that the current feature exists.

I would tend to agree with you that for many installations short-term load fluctuations are normal, expected, and designed for.

I do imagine that it could be useful to configure an alarm just under your breaker trip threshold - especially if a customer is experiencing nuisance trips with equipment start up etc.

NOTE: there is presently an unfortunate firmware bug (to be fixed next release due Q1/Q2 next year) that can result in continuous triggering and alarming when enabled and provided a specific load fluctuation signature.

[sesa70148]

Thanks Dan. If anyone has any additional applications for this feature, let us know. We can look at adding some context to the user manual in a future revision.

[Arneil_Dalope]

Hi Dan,

Fair enough, I also hope that this feature is disabled by default. Currently, the boolean switch for this is the same for the Voltage Sag/Swell. We have created a separate external boolean to disable this.

Thanks,