monitoring software.

Set the UPS shutdown time to 2 minutes, all other settings to nominal, and disconnect the serial port cable from the UPS be- fore running the recalibration. If you leave a monitoring program running through the serial port, it will turn the UPS off early, and you don’t want to do that during a recalibration run. When the run is complete, and the UPS turns off, you can reattach the serial cable, and the normal loads, and recharge the batteries normally. If you think you might have a power outage during the recharge time, allow the UPS to recharge to 20% or so (in- dicated by the panel lamps) before trying to use the computer system. This will allow the UPS to handle short dropouts while it recharges. Of course, if you can leave the computer off during the recharge time, the UPS will recharge much faster.

As an aside, when the batteries failed, my total runtime at 100% charge and an idle state was 9 minutes, which is pretty bad. I replaced the batteries with extended capacity cells, which add about 15% to the stock capacity. Now, after two complete charge/ discharge cycles, 100% charge shows the available run- time to be 42 minutes on the system when it’s idle, and 33 min- utes when the system is very busy. The differences are due to the load of the computer, when the disks are busy, and the cpus are not in a halted state (my system halts the cpus when they are idle, to save power and lower heat, as do other OS like Linux), when compared to an idle state. Apcupsd indicates the load is about 27% when idle, and as much as 37% when heavily loaded.

I’ve found that two charge/discharge cycles result in a more ac- curate recalibration when installing new cells. It appears that some batteries need to be put through a couple of complete cy- cles before they reach their full capacity. I’ve also noticed that the full-charge voltage is different for each battery until they have been through two cycles. On the initial charge of my new batteries, the 100% charge voltage on the two cells was almost

.5 VDC apart. After two complete cycles, the batteries measure within .01 VDC of each other!

I hope this information helps anyone who might encounter the problem I saw, and also shows folks how to recal their batteries. If you haven’t done a complete recalibration in a year or two, I’d recommend it, so that you have warning of a low battery instead of what happened to me.

Regards,

—Carl

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APC UPS control system manual
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UPS control system specifications

APC UPS (Uninterruptible Power Supply) control systems are vital components for ensuring uninterrupted power supply and protecting critical equipment from power interruptions, surges, or fluctuations. Designed by Schneider Electric, APC UPS systems are renowned for their high quality and reliability. They utilize advanced technologies and features to suit diverse applications, from home offices to large industrial settings.

One of the main features of APC UPS systems is the ability to provide backup power during outages. This is achieved through a battery system that activates immediately when the mains power fails. This seamless transition minimizes downtime and ensures that electronic devices continue to operate, protecting data integrity and equipment lifespan.

Another significant characteristic of APC UPS systems is their intelligent management capabilities. Most models come with PowerChute software, which provides users with real-time monitoring of power conditions and the status of the UPS. This software allows for graceful shutdowns of connected devices during extended outages, thereby preventing data loss and damage to devices.

APC UPS systems also incorporate advanced technologies such as Automatic Voltage Regulation (AVR). AVR technology ensures that the output voltage remains stable by correcting minor fluctuations without switching to battery mode. This not only prolongs the battery life but also provides a consistent power supply to the connected equipment.

Thermal management is another critical aspect of APC UPS control systems. The design often includes efficient cooling systems that prevent overheating, ensuring optimal performance and longevity of the unit. Some models feature EcoMode, which reduces energy consumption and lowers operational costs by working at high efficiency only when battery backup is not required.

APC UPS systems are designed with scalability in mind. Users can easily add more batteries or connect additional UPS units to accommodate growing power needs. Features such as hot-swappable batteries and modular design facilitate easy upgrades and servicing without interrupting power supply.

In terms of connectivity, APC UPS products often feature multiple options including USB, RS-232, and network management capabilities. This enables users to connect remote management tools and integrate the UPS with existing IT infrastructure.

In summary, APC UPS control systems deliver reliability, efficiency, and advanced technology features that cater to a wide array of power protection needs, making them a trusted choice for individuals and businesses alike.
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