When you install uninterruptible power supplies, you are connecting a critical power system that will form a vital part of your business continuity plan and building infrastructure. The UPS system must be remotely monitored so that any alarm conditioners are picked up instantaneously and responded to.
Today’s uninterruptible power supplies offer a range of remote monitoring options including:
- RS232 and USB communications
- Simple Network Management Protocol
- Volt-free contact signals
- Modbus and JBUS
Most UPS have an RS232 and/or USB communication port. This can be used to communicate with a locally connected tablet, terminal, laptop or computer running software supplied by the UPS manufacturer. The software may be in the form of UPS management software or UPS engineering software.
UPS management software allows the UPS to be monitored via a computer with status information and alarm messages being displayed on the computer itself. The software may also send out email and text alert messages to predefined addresses and mobile numbers if an alarm condition occurs. At a preset battery runtime level, the UPS can be set to signal the UPS management software to being an orderly shutdown of the computer system.
There are three types of UPS system: standby, line interactive and on-line. Standby UPS are the most basic and cheapest form and may only be supplied with a USB communications port (to reduce costs). Line interactive and on-line UPS may have both USB and RS232 ports.
Line interactive and on-line uninterruptible power supplies designed for network and server power protection applications will also incorporate a slot-in communications card option. This provides the facility to for Simple Network Management Protocol (SNMP) communications whereby a suitably equipped UPS system can be connected to an IT network and given its own IP-address. Communication from the UPS to a central Management Information Base (MIB) is possible and the UPS can be communicate across the network and through UPS management software initiate alarm messages, emails and text alerts and initiate an orderly system shutdown – even in virtual server environments.
For SNMP communications, UPS manufacturers typically provide a LITE version of their management software that allows communication with one UPS over a network. Same brand, multiple UPS communications are generally possible using a licensed FULL version and may be ideal for large or multiple but connected networks sites.
Volt-free contacts (VFCs) are powered relay contacts that open or close dependent upon their configuration and can be preset for a range of alarm conditions. Opto-isolators provide an alternative contact signal source and may require conversion to volt-free for the communication gateway. Volt-free communication provides a simple ‘Go/No Go’ type communication and no management information. As such they may be used to communicate with Building Management Systems (BMS) and other such general alarm/status boards and systems.
Modbus and JBUS are industrial communications protocols using RS232 and/or RS485 signals. They provide more communications information than simple volt-free contacts but for industrial rather than IP-network applications (which require SNMP). Suitable UPS systems can be installed with a Modbus/JBUS adapter card.
Other UPS adapter cards can include serial duplexers that can provide more than one RS232 signal source from a single UPS system and additional Emergency Power Off (EPO) contacts. Most UPS systems will feature an EPO shutdown input contact but for some applications and second system input may be required.
UPS systems can also be remotely monitored via modem connection and some UPS manufacturers offer locally powered modem using GSM cards or local IP-networks. Wireless modems and SNMP card options may also be available.
Where a network-type UPS system does not have a communications slot, adapter cards may be supplied as boxed packaged with their own power supplies. If these are used the boxed device will require its own secure power socket.
Monitoring of your UPS system is important as most uninterruptible power supplies will perform automated self-testing every 24-hours and alarm if a fault condition occurs. The fault may not be serious at first but if left could lead to a situation where the UPS system is not able to support the load and fulfill its critical power role. A typical example could be a failed self-battery test due to a weakening battery block. Over time the battery block degrades further and weakens the entire battery set.
For more information on remote UPS monitoring options please contact the Eco Power projects team on 0800 612 7388 or see our full range of connectivity and software options.