Zucchini busbar systems explained

John Clarke is Director and General Manager of The Zucchini Group in the
UK.  He has worked in the electrical industry for more than 30 years and,
in the last 15 years, has been involved entirely in the development of Busbar
systems in the UK.  Originally with Telemecanique, he was subsequently
appointed Sales and Marketing Manager of Power Centre before founding the UK
operation for Zucchini.

Zucchini are one of the original pioneers and
innovators of Busbar power distribution systems and are now a major player
throughout Europe.

1. What is the history of Zucchini
busbar trunking?
Zucchini busbar trunking has been available for
more than 50 years.  It has progressed from derivations of busbar chambers
with heavy metal gauge, metal closures with bolt-on covers and clamp connections
for tap-offs to totally enclosed sheet steel or aluminium casings with either
copper or aluminium conductors and plug-in, tap-off outlets, which are fully
shuttered and finger protected for increased safety. The latest generation of
Zucchini busbar system design incorporates a 5-pole system which provides the
advantage of a high integrity, 100% separate earth bar whilst also retaining a
full 100% neutral bar.  200% neutral systems are available for applications
with high harmonic currents.

2. What does a Busbar trunking
system consist of?
Busbar trunking is manufactured into totally
enclosed, pre-fabricated sections consisting of copper or aluminium busbars with
current ratings ranging from 25 up to 6300amps.  Power is simply tapped-off
by plugs or tap-offs positioned at regular intervals.  Typically, a busbar
system will consist of 3 or 1.5 metre lengths, end feed/live end boxes, end
covers, and various tap-off units at different ratings and hanging brackets.

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align=right vspace=5>3. What are the advantages of using Zucchini
busbar trunking?
Zucchini busbar trunking has several key advantages
over conventional forms of power distribution:-
a) Reduced, on-site
installation times when compared to hard-wired systems thus leading to cost
savings.
b) Increased flexibility in design and versatility with regard
to future modifications.
c) Increased safety features brought about by
the use of high quality, manufactured components, which provide greater safety
and peace of mind for specifiers, contractors and
end-users.

4. In which applications are Busbars being
used?
Zucchini busbar trunking systems are now being used in a
variety of high and low voltage applications including production plants,
workshops, assembly lines, warehouses, distribution centres, supermarkets,
retail outlets etc., etc.

5. What major UK projects have specified Zucchini busbar
trunking for power / lighting distribution?
Rolls Royce, Rover
Cars, JCB, Honda, Mercedes Benz, Land Rover, Ford, Vauxhall, Caterpillar,
British Telecom, Lidl Warehouses, MEB, Manchester Airport, BBC Television,
Seagate Computers, Tesco, Wickes, Blockbuster Video, Eddie Stobart and HMV, to
name but a few.

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align=right vspace=5>6. Is it difficult to estimate a Busbar
installation project?
No.  The beauty of busbar is its
simplicity – from the design/estimating stage through to installation on
site.  This is because the technical characteristics and price of each
component are always known. Busbar installations require no special tools. 
The joints, lengths and accessories are simply bolted or screwed together. 
The medium and high power systems have double-headed torque bolts, which on
tightening will sheer when the correct torque has been achieved. In addition,
the fact that busbar is a factory manufactured and tested product, ensures a
high quality, safer installation.

Zucchini provide a full range of technical support services to electrical
contractors who can now buy fully designed, engineered systems.  The design
and estimating stages are also fully supported by Zucchini who provide
quotations for busbar components and can in most cases, advise and assist in the
design.

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align=right vspace=5>7. How do Busbar installations compare in
terms of cost?
Most favourably.  Historically, the material
cost of busbar has been a point of concern for electrical contractors. 
However, it is short sighted to compare the cost of busbar against that of a
length of cable - and not the real cost of a cable installation to include
multiple runs of cable, tray and fixing, let alone the protracted time and
effort of the cable pulling operation.

The cost of busbar systems has fallen in real terms over recent years. 
Add to this, the cost saving in installation time – up to 50% less than
cable!  The reality is that electrical contractors can offer a more
competitive bid, at the same time as offering his client a “state of the art”
power distribution installation which is infinitely more flexible in use. 
The installation time for busbar is virtually the same as for installing cable
tray – before the installation of the cables!  This is obviously a very
important consideration in these days of ever tightening completion
deadlines.

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align=right vspace=5>8. How do Busbars operate?
Busbar
trunking falls into two distinct categories – distribution or feeder
busbar.  Distribution busbar distributes power along its length through
tap-off points along the busbar at typically at .5 or 1 metre centres. 
Tap-off units are simply plugged in along the length of the busbar to supply a
load, (this could be a sub distribution board or in the case of a factory, to
individual machines).  Each individual tap-off can normally be added to or
removed with busbar live, thus eliminating production down time.  Used
vertically the same systems can be used for rising mains applications, with
tap-offs feeding individual floors. (Certified fire barriers are available at
points where the busbar passes through a floor slab).  The fact that the
protection devices (fuses, switchfuses or circuit breakers) are located along
the busbar run, reduces the need for large distribution boards and the large
quantities of distribution cables running to and from installed equipment.

High power feeder busbar takes power directly from A to B.  Usually from
a power transformer to switchboard or switchboard to switchboard.  This
basic configuration is often referred to as ‘a goal post installation’. 
However, if a power source is required to be tapped off then it is possible with
Zucchini product ranges to do this at a joint along the run – another example of
the flexibility of busbar

Both feeder and distribution busbar systems in the medium and high power
ranges are available in two forms: the flat spaced configuration where the
conductors are either air insulated or have PVC insulated conductors all within
an earthed metal enclosure, or the sandwich configuration which is becoming the
norm for most manufacturers at these ratings.  Sandwich construction means
that the conductors are individually insulated and mounted to form a sandwich of
conductors and insulation within the busbar casing.  The sandwich
construction busbar has very good mechanical strength, gives higher fault level
withstand characteristics and has lower volt drop characteristics.  This
type of busbar is a very compact product making it ideal for installing into the
ever-reducing available space which is allowed in the modern building for
building services!

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align=right vspace=5>When used for rising main application, the sandwich
configuration negates the need for fire barriers because there is no air gap
within the casing to give a chimney effect which would allow the passage of
smoke and fire.

9. Do busbars have IP
ratings?
Most of the Zucchini busbar systems have IP ratings up to
IP55, which allows them to be used in difficult environments. 

10. What are the aesthetic advantages?
Where
aesthetics have to be considered, Zucchini busbar trunking can be installed with
natural galvanised, aluminium, or painted finish.  Special colours to match
switchboards or a specific colour scheme are also available on request.

Another point to remember is that when comparing with cable, busbars are more
compact when installed because allowances for large bending radii are not
necessary – an important consideration in view of the smaller switchboard rooms
now being made available.

11. To summarise
Busbar is a growth concept in power
distribution. There has never been a better time for electrical contractors to
consider using Zucchini busbar systems. Zucchini offers a full technical backup
– from design to installation support.  The competitive price levels of
Zucchini busbars combined with the time saved on site, along with other benefits
discussed, make busbar trunking systems a must for today’s power distribution
installation!