The GFU08 series of robust and modular gas cylinder transport carts are used for the filling and refilling of SF6 gas in the required gas compartment. The modular design enables worldwide application through the various mechanical and electrical connections.
The model range is split into 4 versions:
- Model GFU08-B: Filling cart
- Model GFU08-W: Filling cart with scale
- Model GFU08-E: Filling cart with vacuum pump
- Model GFU08-C: Filling cart with scale and vacuum pump
Models GFU08-E and GFU08-C are fitted with vacuum pumps. With these, the air is extracted from the SF6 gas compartments so that, afterwards, a professional SF6 gas filling can be made. The 16 m³/h vacuum pump built into the models GFU08-E and GFU08-C as standard, enables a fast evacuation down to < 1 mbar (0.75 Torr). For larger volumes, suction of up to 40 m³/h is available as an option. With 2-stage pumps, the end pressure can be reduced to as far as 2 x 10-3 mbar. The risk of either too high humidity or air concentration in the SF6 gas compartment is therefore not a consideration.
With the models GFU08-W and GFU08-C, a gas cylinder scale is built in, which enables the exact determination of the amount of SF6 gas filled in. Thus, the gas filling cart is an ideal tool for using the mass-balance method in accordance with the IPCC directive for the preparation of emission reports.
The special, flat design of the weighing cell under the gas cylinder allows easy loading and unloading of the heavy cylinder by only one person.
Prior to the first filling with SF6 gas, the gas compartment, vented immediately before, is evacuated with the optionally available vacuum pump. The consequent isolation of the hoses for the vacuum and filling function ensures that, in no case, can SF6 be released accidentally into the atmosphere. The cross-sections of the vacuum hoses have been optimised for each pump power (DN 8, DN 20). At the same time, the number of connecting parts has been kept small in order to minimise the risk of potential leakage. The better the final vacuum, the lower the concentration of unwanted air and humidity. The variety of vacuum pumps selectable can meet the different customer requirements in terms of evacuation time and final vacuum. The high purity of the SF6 gas filling is extremely important for the safe operation and low maintenance of SF6 gas-filled systems.
For the SF6 gas filling, the operator sets the required filling pressure. The filling hose is connected to the equipment via the self-closing valves. Before starting the filling process, the weigh-scale display is tared; thus the SF6 gas fill-level can be easily read. With a dedicated button, toggling between gross
and tared load is possible.
The optional integrated scale in the GFU08-W or GFU08-C model series has been designed for an accuracy of better than 0.02 %. The battery powered, 6-digit LED illuminated LCD display is particularly suited for this mobile application, with its IP 65 ingress protection and maximum 75-hour battery life. It is possible to set the time delay after which it is automatically switched off when not in use. Furthermore, the backlighting can also be switched off, in order to increase the battery life. The charging cycle is indicated via a red/green charging light.
With the help of the self-storing ratchet strap, the gas cylinder can be easily secured onto the transport cart with maximum safety. The easy-to-use strapping to EN 12195-2 can apply a lashing force of up to 250 daN.
Through the balanced design and excellent running characteristics of the large wheels, the transport carts are particularly suited for use in indoor switchgear (optional pneumatic tyres for outdoor switchgear).