SPECIAL FEATURE
QuietAir e-gift vouchers
SPECIAL FEATURE
COMMERCIAL VEHICLES & EV INFRASTRUCTURE
magnetic saturation . A 50Hz residual current IRac ( I ) equal to the tripping value sensitivity , produces a magnetic field 0 to B1 for the + ve ½ cycle . The resultant change in this field as IRac passes through zero for – ve ½ cycle induces a proportional voltage ( II ) in the trip circuit winding and would result in the RCD tripping . A residual current with + ve biased DC component
IRdc > 6mA , passing through the toroid will shift the operating point of the magnetic material on the H axis to the right . Now if a residual current IRac with the same value as ( I ) flows the combined current IRdc + IRac ( III ) produces a magnetic field B2 to B3 . Although the amplitude of ( III ) is similar to ( I ) the resultant voltage ( IV ) induced in the trip circuit winding is lower and not sufficient to trip the RCD due to the effect of the smooth DC content .
EV infrastructure- RCDs
In installations containing RCDs in series , the residual currents flow through both the EVCP RCD and the upstream RCD as can been seen in the following examples :
Figure 2 The feeder pillar distributes power to 1 EVCP , the leakage currents and residual currents flow through both upstream and downstream RCDS . Using an RCD that monitors the level of DC residual current at the EVCP and switching off the CP if the 6mA threshold is exceeded enables the use of Type A RCDs upstream RCD .
Figure 3 The upstream RCD mounted in the feeder pillar will be subjected to the combined leakage currents of the connected EVCPs and must be selected accordingly . In this case a Type B RCD is required upstream , as the combined DC residual current may exceed the safe limit for Type A .
Figure 2 . |
Specify the correct RCD
Local authorities and private companies offering public / staff charging facilities have little control over the EVs connected to their EV infrastructure , and therefore need to cater for the worst case . Options to monitor DC residual currents within the EVCP improve the safety performance of installations containing Type A RCDs .
For complete safety requirements refer to the IET Wiring Regulations BS7671 2008 Amendment 3:2015 Section 722 and the IET Code of Practice for Electric Vehicle Charging Equipment Installation .
|
Figure 3 . |
EARN POINTS WITH EVERY QUIETAIR FAN PURCHASED
The Quietest Fan Beware of Imitations *
QuietAir e-gift vouchers
QT150 QT120
QT100
OMG m8t have u heard bout QA
£ £
PROMO
Who hasn ’ t , 1QA =£ 2,10 =£ 20 e-gift voucher and build , will def do
Also have u heard bout sick motor u
£ £ can win ?
££££££££ 4 real
£ £
Spend at over 100 leading retailers
* On both speeds , the QuietAir100 unlike other silent fans on the market , complies with current Building Regulations Part F and Part L plus it meets the installed performance requirements when ducted as per the Domestic Ventilation Compliance Guide with class leading energy levels for toilet , bathroom , utility and kitchen extraction .
Terms and conditions apply visit airflow . com
Free Entry To Win a Ford Transit Custom Van
airflow . com / promo Call : 01494 560800