SCL500RM1UC and very short power outages

[lsc]

Hi All,

We've got 3 SCL500RM1UC UPS units installed, each protecting a single switch (load is around 10-15%)

The power in the area isn't the best and we occasionally have very short "blinks" in power lasting a second or 2

Today we had one of these short "blinks" in power and 2 of these units remained on battery, even though the mains power was restored, in Smartconnect the units even said there was mains power available, but they remained on battery which eventually depleted and turned the switch off - not great

What would cause this behaviour, is it a sensitivity setting or other setting we need to configure using Powerchute (support suggested this), or has anyone else had this same issue with the SCL series?

We use the larger 3kva units in our server rooms and don't have issues like this with UPS' getting stuck on battery even though there is mains power available

The electrical work is brand new and is known to be good and working

[Szabi]

Hi,

The following scenarios come to mind that can potentially result in the UPS staying on battery even if utility power is available:

• Utility power is available, but input voltage or frequency are not in range for online operation. In systems where there is a generator backing up the AC supply, input voltage or frequency may be out of range, depending on the power quality supplied by the generator (this may only be relevant if there is a generator backing up the utility supply)
• Utility power is available and in typical range, but still under (or over) the hysteresis point required for the system to transfer to online operation; there is a hysteresis in place that needs to be met before the UPS transfers from on-battery to online state. This is to prevent constant switching to battery and online. Power cycling the UPS resets the hysteresis so when the unit is powered on again, it will likely start, and stay in online state.
• Utility power is available, but circuit or branch supply is unavailable, potentially due to the upstream circuit breaker or branch protection tripping during the weather event