FrontierDC’s enabling technology partner, Cannon Technologies, was approached by its client working on behalf of Network Rail; they were looking for a cabinet to hold new electronic equipment to be used on the upgrading of the “Customer Information Technology System” being rolled out across the infrastructure particularly at the un-manned stations. It would also incorporate the CCTV security systems being installed.
Unable to find an existing cabinet solution an initial “Request for Information” was put out to the market, Cannon responded and was selected to put a full specification together and manufacture a prototype cabinet for integration and compliant testing.
The cabinet selected by Cannon was to the Cannon Technologies drawing number S143800F.
The cabinet was configured with fully locking doors to both front and rear faces allowing for access from both sides of the electrical equipment being integrated. The construction of the cabinet consisted of a dual skinned, thermally insulated chamber for maximum protection against the effects of both the solar gain and long wave radiation.
The cabinet was designed to be installed onto a standard Network Rail pre-cast concrete plinth.
The proposed cabinet, S143800F was cooled using “Forced Fan Ventilation” giving a Δt (delta t) of between +5ºC and +7ºC depending on the surrounding ambient air temperature. This was achieved by using two radial blowers, each fitted with finger guards for operator protection during periodic servicing requirements. These were positioned within the hinged roof void giving an N+1 solution. The roof was supported in the open position by a bonnet type stay bar.
The fan type selected was based upon the heat being dissipated by the internal equipment and the effect of “Solar Gain” upon the outer skin of the cabinet. The “Forced Fan Ventilated” system works by drawing fresh ambient air into the cabinet through replaceable filters incorporated within the doors which also have in-built bug screens. The filters have a large dust holding capacity so cleaning/replacement can be accommodated within the normal equipment maintenance routines.
The fans are powered via an independent 48-volt DC power supply, and are fully controlled and monitored via a “Cannon Guard” system. Please see our literature and video on the Cannon web site entitled “Cannon Guard”.
The Environmental Monitoring and Control system (EMC) controls the fan speed against temperature thus giving a cost saving to the customer by reducing the fans speed during low temperature conditions. It also provides any alarm contacts required, typically temperature out of limits, door open, fan failure etc.
Internally mounted within the thermal chamber and positioned to the underside of the internal roof panel would be a low power AC LED strip light, this would be switched on the door being opened.
Cannon also provided integration of a small 6-way consumer unit complete with a double pole 100-amp RCCB incomer and 6-off 20-amp single pole MCB’s all mounted on a 5-U high mounting bracket which also carried a13-amp dual RCB socket for use during customer configuration and site testing/set-up.
Cannon terminated the alarm output connections onto a 1-U SNMP Cannon Guard 405E-N3SP-2A controller which was fitted within the 19” rack, details of the unit can be found on other Cannon documentation.
The general internal integration consisted of ESD button, fitted and labelled and located close to the mounting rails, all terminals were labelled and earth bonding labels attached to the bonding points for clarification. All electrical work carried used our qualified and approved electrical engineers; it was fully tested and certified.
Cannon Technologies Ltd can confirm that the prototype has been accepted by the customer and many cabinets have now been manufactured and installed across the rail infrastructure.