The power factor issue only relates to ac machines
The windings represent an inducitve load and this produces a lagging power factor
a pf = 1 is perfect! and 0.9 is better than 0.6 etc
The circuit must be capable of supplying this unwanted current so cables and switchgear must be sized up to...
Sorry Jeremyd
But you cannot get a free copy!
I've just ordered 15 copies for my students and tried to find a free source
Typical cost is about £45 and dont forget the IEE On-site guide at about £14 because not all the info is in BS7671
You can get a version on CD-ROM
You may get some useful...
Picking up on some of CurtBs points
Single insulated hand tools etc require a cpc earth wire as the safety conductor
If the earth wire breakes then the safety conductor is lost increasing the users risk of electric shock
Double insulated tools do not require an earth wire as the protection...
BS 7671:2001 the Blue copy of the IEE Regs Part 6 contains Section 601 which deals with locations containing a bath or shower
The room is now divided up into Zones 0,1,2 & 3 according to risk when electricity and water meet
Zone 0 is the interior of the bath or shower basin
Each zone has a...
Insulated pull cord operated switches complying with BS 3676 are permitted in Zones 1 & 2 of a bathroom installation Reg 601-08
You can also mount a conventional wall mounted switch outside the door to control the bathroom light as an alternative option
In UK we rely on EEBADS to protect people & livestock against shock risk from indirect contact
For circuits supplying socket outlets the protective device must disconnect the circuit under fault conditions in 0.4 seconds or better
We can install a 30mA RCD on the circuit to provide protection...
In the UK doing an electric strength test using the "withstand test"
Ideal test temp 15C to 25C at atmospheric pressure
Set gap to 4mm
Fill container and start testing within 10 min
Increase test voltage in 2kV steps upto 30kV for 11kV oil sample
If test fails carry out two further...
In UK circuit must have a 0.4 sec disconnection time
Watch out for supplementary equipotential bonding
A 30mA RCD can be fitter to reduce shock risk
Read BS7671 Part 6 Section 601 for Locations containing a bath or shower
The main driver in the UK is the Electricity at Work Regs 1989 which is the statutory document
Designing to BS7671 is considered a "good interperetation" of this set of Regs - BS7671 itself is not statutory
For all UK electrical systems the statutory document is the Electricity as...
Hi Redwing its me again
I've dug up the following info which may help solve your problem
We used 90A Fuses ESI REF IIOIL10 in FRUM'S on 100KVA TX'S. Manufacture ref as follows
B.S.= OQGRN 90A G.E.C = KEMXO 90A & Brush OHGMA 90A
The max size LV fuse we would fit to discriminate was 600A
The HV...
As you say lee5 TN-C or PEN conductors are not very common
Do you need a neutral if the motor is a 3 phase balanced load or is the neutral required for a control circuit function?
RCD's will not operate with a PEN conductor on their upstream side under earth fault conditions
BS7671 has quite a...
