Continuous power monitoring systems from Bender UK are designed to monitor and provide early warning of developing earth faults, removing the possibility of unnecessary power interruption and unplanned shutdown.

Tier 3 and 4 data centres are designed with redundant power from source to socket, to cater for any eventuality resulting from a single failure.  But power outages in data centres can still occur.  Redundant designs are deemed to be concurrently maintainable but switching off systems even for periodic inspection and testing carries with it the restart risk.

Bender residual current monitors (RCM) are used to monitor earthed systems (TT and TN systems) for fault currents or residual currents. They continually monitor insulation levels, providing early warning of earth faults and notifying the end user before the shutdown threshold is reached.

Continuous monitoring also enables data centres to fulfil the requirements for regulatory checks without shutting down the power.  This enables the data centres to provide continuous, reliable service to customers and removes the risks that accompany even the most meticulously planned restart.

Downtime in colocation data centres is especially difficult, as a large number of customers’ data is located in one data hall. Bender UK’s residual current monitoring solution reduces the headache involved with having to agree and organise a single maintenance shutdown period that pleases all your customers.

Meet the requirements for periodic inspection and testing (PIT) without shutdown

Power shutdown during periodic inspection and testing is intrusive and provides only a snapshot of the status of a power system. All other tests during periodic inspection and testing can be carried out either with power on or with minimum disruption at circuit level.

Bender UK continuous residual current monitoring enables the data centre operator to meet these regulatory requirements without power shutdown.

BS7671:2018 651.2 states: “…Where a circuit is permanently monitored by a residual current monitor (RCM) or insulation monitoring device (IMD) it is not necessary to measure the insulation resistance if the functioning of the RCM or IMD is correct…”

Why monitor residual current in a data centre environment?

Due to the nature of the loads installed in data centres, use of residual current devices (RCDs) is not recommended because of their nuisance tripping problems. By using Bender technology to monitor the RCD, any deteriorations are detected very early on before the shutdown threshold – ensuring reliability and allowing for smooth running of your data hall.

It is particularly important to examine the detail of power system performance; to detect and evaluate fault currents, equalising currents and insulation faults in a finely granulated way. Insulation faults, stray currents, overloaded N conductors due to harmonics or asymmetrical loads, interruptions of PE and N conductor and also EMC influences can interfere with the entire current supply system and have an impact on the operation.

The impact can range from triggering several protective devices, and unexplainable malfunctions of protection or IT systems to fire damage or even injury to personnel.

The advantages of Bender RCM technology have been proven through its use in large data centres in Europe, delivering safer and more reliable systems and greater availability by providing advanced warning on developing insulation faults. Another benefit is the ability to pinpoint the location of an earth fault.

Continuous residual current monitoring using Bender RCM technology enables effective monitoring of power infrastructure, as well as cabling it also monitors the status of connected equipment including servers.

Bender technology also enables the operators and users to tailor the system to meet their individual requirements – supplying a bespoke solution.  The RCM threshold response value and the time delay can be adjusted to precisely match the requirements of each individual location, which means that known sources of errors and transient faults can be masked. If a residual current exceeds a defined threshold value, the RCM system sends a warning to the building control system, identifying problems and issues before they become critical.

Residual current monitoring instantly alerts the control centre if a problem begins to develop, equipping the operators to take action before the problem becomes critical.

Data from the RCM system can feed into a normal PC or laptop on site, or to your data centre infrastructure management software. Data can also be monitored remotely using the internet to securely log in and check the status and performance of one or multiple sites.

To find out more about how Bender UK can safeguard data centre availability and identify issues before they become critical visit stand D953 at Data Centre World or go to