|Equipment and systems covered by this certificate are as follows:|
The 900-2800 Frame, 18 Pole, 1960kW, 6.6V, 50 Hz TEAAC Induction Motor comprises a fabricated steel motor casing employing a closed internal cooling air circuit, which is cooled using a fabricated steel air to air heat exchanger mounted above the stator housing. An internal fan is located on the rotor within the frame at the drive end for the circulation of the internal air around the windings and through the heat exchanger. An external fan is attached to the external rotor at the non drive end of the motor for the circulation of the external (cooling) air. The rotor is supported by frame mounted bearings at both ends.
The motor and cooler, together with the neutral point terminal box are designed to be purged and pressurised by a control system of the Leakage Compensation Type, using air as the protective gas from a compressed air supply. The assembly is therefore provided with an inlet for the pressurisation and purging air and external pipe work forming an air distribution system. A pressure relief, flow monitoring and spark arresting device is provided at the top of the cooler for the exit of the purging air. The enclosure low pressure monitoring port is on the side of the enclosure, on the low pressure side of the internal fan. Metal pipe work connects the port to the low pressure switch of the pressurisation and purging control system.
The main terminal box is increased safety to IECEx BAS 08.0021U. Additional increased safety terminal boxes to IECEx BAS 08.0021U are provided of the connection of the increased safety space heaters to IECEx BAS 06.0081U, current transformers, bearing and stator resistance temperature devices.
In addition, the following electrical devices form part of the motor assembly, and are certified as independent equipment:-
i) A Purge and Pressurisation Control System manufactured by Expo Technologies to IECEx SIR 07.0027X, coded Ex [px] IIC T6 (-20°C to +55°C) Gb. In addition there is an associated Expo Interface Unit to IECEx ITS 10.0003X marked Ex e IIC T5 Gb (-20°C to +55°C).
ii) Bearing Temperature Probes manufactured by Okazaki Manufacturing Company to IECEx BAS 08.0094, coded Ex de IIC T6 (-50°C to +60°C).
iii) Bently Nevada Vibration Sensors to IECEx LCI 06.0003X, coded Ex ia IIC T4 (-40°C to +100°C) Ga. Terminal facilities are provided locally for these intrinsic safety circuits, for mechanical protection purposes these are housed within a stainless steel enclosure.
The free (net) volume if the motor and cooler assembly is 20m3.
Internal earth connection facilities are provided at the main terminal box, and an external earth bonding facility is provided on the motor frame.
The motor is rated at 1960kW, 6.6kV, 3 phase, 50Hz, for S1 duty as defined in IEC 60034-1 and is for connection to a three phase supply having form and symmetry not worse than that defined in IEC 60034-1.
|CONDITIONS OF CERTIFICATION: YES as shown below:|
1. The enclosures are purged with air at a flow rate of not less than 4m3/min for a period of not less than 60 minutes.
2. Each and every machine is to be subjected to an internal overpressure test of 45mbar for two minutes, followed by a leakage test at 30mbar. The leakage shall not exceed 1.2m3/min.
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