Whilst oil based equipment might have operated reliably for the past sixty years, there are many reasons to consider retrofitting, specifically:
- Fault level upgrades - this is where the fixed portion needs to be compatible with a proposed enhanced rating
- Remote control of switchgear – many originally manufactured ocb’s have manually operated (type XM) mechanisms that cannot be converted to electrical release (type XE) or motor charged (type XEM) mechanisms
- Troublesome individual breakers on a multipanel switchboard where there are no technical or economical reasons to change the switchboard
- Desire to upgrade the moving portion but cannot practically consider installing new switchgear (i.e. process industry)
- Less maintenance and asset management costs (no oil, frequency of maintenance reduced, post fault maintenance reduced)
- Loss of expertise on particular ranges of circuit breaker
- Lack of availability of spares for oil circuit breakers
- Change of duty – increased frequency of switching
- Increase in circuit rating from 400-630A (or upgrade from 400-1250A if other internal components changed)
No busbar outage is necessary to conduct the retrofits so there is no interruption of service.
When retrofitting circuit breakers that are utilised for direct on line motor starting, consideration should be given to the installation of surge arresters.
Why use Switchgear Support Ltd?
Through current and former employment, we have experience with over 5,000 retrofits and also been involved in some of the largest HV retrofit contracts in the world. We can offer the complete package from initial consultation to choice of breakers to final removal and disposal of the original breakers via fully licensed means.
In particular we have extensive knowledge of Brush Switchgear type VSI (single busbar), VTD (double busbar) ranges and South Wales Switchgear type C/D ranges of retrofits with unparalleled knowledge of the original fixed portions of switchgear.
Taking advantage of individual circuit outages, we can:
- Convert existing oil filled VT's to cast resin VT's
- Upgrade existing current transformers to suit better protection and metering
- Alter protection relays from electromechanical to electronic
- Supply and install telecontrol facilities for remote control and indication
We are also able to retrofit the following types of equipment:
- Brush Switchgear VBA/VBC/VBAD/VBCD
- Reyrolle LMT, LMT23T, LMT2 ranges
- GEC BVRP17 and AEI BVRP
- Other manufacturers such as Ferguson Palin, English Electric, Met Vic, Crompton Parkinson, Statter, Johnson and Phillips, etc.
For all retrofits offered, the circuit breakers have been fully type tested to IEC60056 or IEC62271. The certified ratings are:
- Rated Voltage 12/13.8 kV
- Rated Current 400A- 1250A
- Frequency 50/60 hz
- Symmetrical breaking current 25kA
- Rated making current 62.5kA
- Rated Power Frequency withstand 28kV
- Basic Impulse level 75/95kV
- Short time current (3secs) 25kA
Relevant Case studies:
For the Brush Switchgear VSI/VTD range of switchgear, we can offer certified ratings of up to 2500A, 31.5kA.