Machine standstills occur from time to time and result in energy being consumed for nothing. The drive motor and the heaters are in operation but no production takes place. The standstill supervision is a special program available for Netstal's control generations DSP/1-5. The purpose of the standstill supervision is to avoid an unnecessary consumption of energy during standstills (for e.g. setup, maintenance, disturbance). A machine's power consumption in standstill with closed safety cover can amount up to one third of the consumption in production.
Moreover, reduced temperatures can help to protect the moulding material from degenerating.

Reactive current (also called blind, idle, inactive or wattless component) is caused by electrical consumers (devices) equipped with magnet coils such as motors, transformers and choke coils on building up the magnetic fields. The consequence is that the live lines at this consumer and in the power grid before it are subjected to an additional load. The reactive current thus calls for bigger line cross sections and results in higher losses of energy in the transmission. This is why, in most industrial, trade and service operations, one measures not only the consumed active energy, but also the reactive energy. The so-called power factor (PF) cosφ reveals the ratio between consumed active energy [kWh] and the caused reactive energy [kVar]. If a customer's reactive energy exceeds the limit value of cosφ = 0.9 as defined in the (Swiss) tariff guideline, a part of the reactive energy is also invoiced to the customer by the electricity works. Netstal offers an open-loop reactive current compensation matched to the size of the drive concerned for mounting or installation. A simple and cost-effective solution which helps to save energy costs.

A considerable energy saving potential can also exist at the heaters. A better insulation of the plasticizing unit can reduce the power consumed for heating. This decreases also the radiation to the environment and thereby has a positive effect on the climate in the premises. An aspect which is particularly appreciated where production takes place under clean-room conditions. The heater covers consist of a needle-punched glass non woven sewn into a wear-resistant glass fabric. The savings potential depends heavily on the particular machine applications and amounts to approx. 5 - 45%.

Measurements at machines have shown that parameter changes influence the energy consumption. Netstal offers now integrated power measuring to enable the customer to adapt the moulding process also with a view to the energy consumption. The power measurement helps also to calculate the production costs. Displayed on the machine's screen is the energy consumption per kilo of shot weight in the application on hand, a value which can be used in the cost calculations. The special execution "Power measurement" follows EUROMAP60. EUROMAP60 determines a machine's specific energy consumption and will be applied by most machine manufacturers in future.

Contact: nsc(at)netstal.com