Moeller supplies distribution products for PDUs

Edited by the Engineeringtalk editorial team Apr 6, 2009

Distribution products from Moeller are at the heart of a flexible design for data centre power distribution units (PDUs), which have been developed and implemented by Stroud Switchgear.

In the past, there have been two main approaches to the production of data centre PDUs.

The first is the use of standard distribution switchboards.

This approach is cost effective and, as the boards are standard products, delivery times are usually short.

It is even possible to incorporate, without too much difficulty, some of the special requirements that relate to PDUs, including, for example, a shunt tripping arrangement on the incoming switch and locking facilities on the outgoing MCBs.

Unfortunately, some of the other essential PDU requirements, such as an emergency power off (EPO) pushbutton and surge protection provisions are less easy to incorporate.

In addition, the metalwork of standard switchboard assemblies is often not entirely suitable for PDU applications.

For example, various plinth options are often desirable so that the base of the unit can be accurately aligned with the false floors commonly used to facilitate cabling in data centres.

To address the limitations of standard switchboards, many PDU suppliers have in the past turned to completely bespoke designs.

Provided that they are well engineered, these can do all that is required of them, but they too have shortcomings - because they rely on built-to-order metalwork, they are costly and delivery times are often protracted.

Seeking to provide a solution that would combine the versatility of a custom PDU with the low cost and fast delivery of a standard switchboard, the engineers at Stroud Switchgear decided to adopt a middle path - the use of standard enclosures fitted with off-the-shelf switchgear products configured specifically to meet the requirements of PDU applications.

'We selected distribution products from Moeller as the basis of our PDUs for several reasons,' said John Amos, electrical sales engineer of Stroud Switchgear.

'The products are compact yet easy to work with and they have an attractive appearance, which is important as PDUs are often installed in office locations.

'Moeller also offers a range of products that covers all of our needs, which include such key accessories as surge protection sets,' he added.

A typical PDU produced by Stroud Switchgear on the basis of its new design comprises a 250 A Moeller N Series main incoming switch with shunt trip and surge protection, and two of the company's 72-way single-pole MCB distribution boards, fitted with PLSM Type C breakers.

Provision is made for local or remote connection of an EPO pushbutton.

All of the indicators and displays associated with the equipment are visible through a glazed door, allowing the status of the installation to be seen at a glance.

The MCBs and surge protection devices are fitted behind an internal hinged door that can be opened only by authorised personnel.

The equipment is arranged so that, when the internal door is open, it is easy to use thermal imaging equipment for routine maintenance checks on the PDU.

'Our PDUs are flexible enough for us to meet even the most demanding of requirements without having to make compromises, yet they are competitively priced and we can supply them on short deliveries,' added Amos.

'Thanks to our use of distribution products from Moeller, they offer high levels of safety and reliability.' PDUs from Stroud Switchgear are available with a range of electrical and mechanical options.

They can be supplied with various types of incomer and MCB configuration to suit specific requirements, and it is possible to configure the system to include L2 metering.

The paint finish colour can be customised and plinths can be supplied for either standard installations or for use with suspended floors.