How We Construct Our NH PDUs:
What is a PDU?
A Power Distribution Unit or PDU acts as the internal regulator for all of our National Highways (NH) approved products, making sure the electrics are well regulated and secure.
Our PDUs were developed in collaboration with leading engineering company WSP and with National Highways and posses dual functionality, distributing power for both communications and external electrical devices.
The standard PDU model can be fitted within our NH640 and NH609N Cabinets, and contains only one MS4 circuit, meaning it can be used with any type of National Highways applications, from street lighting to CCTV, by using Adaption Kits, that the customer can purchase depending on their need, making them extremely versatile.
Different PDU Variants:
We have manufactured two different styles of PDU for various different functions: Rural and Gantry.
Our Rural PDU is almost exclusively at ELV (Extra Low-Voltage), and is meant for smaller electronic equipment, i.e. post mounted signals and mast mounted CCTV.
The Gantry PDU contains more equipment inside, and distribute mains power to final circuits, including lane signals, speed enforcement equipment and sign lighting. These are recommended for bigger electricals.
The different applications are all catered for by adding the corresponding Adaption Kits to the PDU.
Check out the video below to see one of our PDUs being built from scratch.
What do our PDUs contain?
Ritherdon manufacture two different variants of PDU, a rural version used on remote locations to provide power to post mounted equipment using Adaption Kits and a Gantry version that can be utilised with the Adaption Kits to provide power to varying Gantry mounted equipment.
Cable entry points for 3off 32mm stuffing glands, 9off 25mm stuffing glands and 18off 20mm stuffing glands all pre-punched and blanked off to ease on site installation and the fitting of any further equipment required.
All components are DIN rail mounted and secured in place using end stops and solid full height blanks.
The bottom row of the PDU (Panel 5) is used for all incoming and outgoing cables, it has fitted a separate removable panel and is fitted with WAGO Topjob terminal blocks to ease the installation of cables, space has been provided underneath the terminal blocks for helix coils.
Panel 4 is the connection point for the main incoming feed. A double pole 100A isolator is used on this row and is also a lockable device.
As per MCX8001 Type 1, 2 & 3 Surge protection is fitted to provide a reduced let through voltage that internal rack mounted equipment can withstand.
The Gantry variant PDU comes with a part populated Panel 2. A double pole 63A isolator is fitted for the fitting of up to 8 AMI’s.
As standard a double pole Type A RCD is fitted feeding a 20A fuse carrier to provide power to 1 MS4. 5 spare ways are reserved on the row for either Speed enforcement equipment or a 2nd message sign.
The final circuit on this row is for ADS-lighting which uses a Double pole 63A isolator with 4 blank ways for the fitting of the ADS- Lighting adaption kit. This variant comes with a rotary isolation switch that will isolate all gantry circuits.
The top row of the PDU (Panel 1) is for all final internal circuits provided, a Type A 63A RCD protected circuit for the pre-fitted heater and Maintenance socket and as well as a spare, if a Fan kit is required using Type C 6A MCBs.
Individually protected via 6A RCBOs with 8off IEC C13 kettle leads, 1off 13A socket bar and 1 spare which provide power to the Comms equipment of the cabinet, power to the RCBOs being fed through a double pole 63A lockable isolator.
Two Double pole isolators are installed on the top row separate to the aforementioned circuits, one to provide power for a post mounted Adaption Kit and the other for a 2nd local cabinet.
All PDU’s go through functional testing before they are delivered to either National Highways stores or direct to site.
PDUs and Adaption Kits
The PDUs used in combination with Adaption Kits are designed to encompass all the different highways applications into one neat solution.
Together with National Highways Cabinets, to house and protect the PDUs, Adaptions Kits and additional customer equipment, they make a well rounded solution to improve the installation of the Highways technology to operate the road network.
For further information on the PDU options available find them listed along their corresponding Highways Cabinet – NH640 Combined Equipment Cabinet in the Options tab as well as the NH609N Cabinet under the Options tab. To further complement the NH Cabinets available and help with installation, browse the NH Pedestals or Standoff Bases.
