Electricity + Control March 2019

DRIVES, MOTORS + SWITCHGEAR

Aluzinc provides for longer life motor control centres

difference, which is the powder coating of steel panels complicates the earthing re- quirement on an MCC, as the paint layer insulates the panel and prevents conduc- tivity. “This means technicians and install- ers must take special care to ensure that proper contact is made between the unit and the earth connection,” he says. For instance, the use of star washers must be strictly enforced among installa- tion staff. Alternatively, certain areas of the MCCs can be left unpainted to allow for earth connections. Kohler points out, however, that this raises the concern that it only takes a small oversight and the earthing will not be fully effective.The use of Aluzinc eliminates this issue as there is no longer a paint layer between the earth connection and MCC panel. There is also the possibility of painted parts being scratched or damaged during transport and installation. When this oc- curs, it leads to the time-consuming task of their being returned to the factory for repeat powder-coating, further delaying installation and commissioning. Addition-

The replacement of steel by Aluzinc in the manufacture of Shaw Controls motor control centres (MCCs) provides a range of benefits to customers, according to the company’s Senior Manager Opera- tions, Anderson Kohler. “Traditionally, we used only steel for our MCCs and steel needs to be pow- der-coated to protect it from corrosion,” says Kohler. “This made completing our products a long process, one that the use of Aluzinc can now simplify and speed up.” The usual process of preparing the MCC panels includes welding, grinding and pre-washing before the powder-coat- ing painting process can take place. These phases can now be bypassed by using Aluzinc, a material that effective- ly resists corrosion without a protective coating being applied. Aluzinc comprises 55% aluminium, 43,5% zinc and 1,5% silicon and offers an extended lifespan. Manufacturers of the product guarantee it will last for about 35 years before any major maintenance is required. Kohler explains another point of

ally, if there is a need for re-welding, the process of grinding and pre-washing has to be repeated before painting again. Kohler highlights that the corrosion-re- sistant properties of Aluzinc allow parts to be kept in stock, ready for quick assem- bly, whereas this is not possible with mild steel due to its potential corrosion. “By introducing the use of Aluzinc in the manufacture of our MCCs, we can reduce the lead time on components by as much as two to three weeks. This is a time-sav- ing that we can pass on to our customers, delivering more quickly,” he says. Part of the ZestWEG Group, Shaw Con- trols has over 30 years’ experience as a manufacturer of quality MCCs, distribution boards, medium voltage (MV) switchgear, control desks, PLC and instrumentation enclosures, portable and containerised substations, E-houses and various other electrical enclosures. The company’s Rob- ertsham facility is ISO 9001 accredited. Enquiries: ZestWEG Group, Africa. Tel +27 (0)11 723 6000 or email marketing@zestweg.com