ELECTRICAL DESIGN REQUIREMENTS. The requirements for the design of the electrical distribution system and the morality lighting shall be submitted to the Town of Ajax for review and approval prior to the commencement of the design.
ELECTRICAL DESIGN REQUIREMENTS. The existing transformer specification is as follows: Secondary Primary 70kVP 1370mAM 380V 252A The existing transformers are rated to supply 270.4µA/m2 to the field. It is the Contractor’s responsibility to design and provide a single adequately sized HFPS unit per field for the application at Duvha Power Station that has as a minimum the following secondary output rating: 80 1900 The minimum method of cooling employed is Oil Natural Air Natural (ONAN) taking site altitude and temperature rise into consideration. Based on the applicable ambient and environmental conditions ONWF (Oil Natural Water Forced) cooling is not preferred. High Frequency is defined as operating at 20 kHz or above on the secondary side. The Contractor supplies a three-phase HFPS that shall result in the ESP efficiency improvement and yield an overall optimal output. The scope includes but is not limited to replacing the first 3 fields’ conventional Transformer Rectifier with the HFPSs on both casings per unit. It is not the intent of this project to change the existing electrical power reticulation including the power supply configuration as much as possible. • The expectation is that the 1250kVA Precipitator Transformer must be adequate for the installation of HFPS on the first 3 fields. • The Contractor notifies the Employer by means of a power reticulation study whether the 1250kVA Precipitator Transformer is adequate to accommodate HFPS on the remaining fields to allow the Employer to make the necessary arrangements to accommodate HFPS’s at a later stage on the remaining fields. • The Contractor verifies the phase balancing on the remaining fields that are fitted with Rectifier Transformers after installation of the HFPS on the first 3 fields. The new HFPSs are adequately designed to operate optimally under the following abnormal conditions. • The new HFPSs must be adequately designed to operate optimally under the following abnormal conditions: o Continuous primary voltage overloading at 110% and undervoltage of 90% of the transformer design o The HFTs should comply to the volt dip immunity criteria as per Eskom standard 240- 56361454 for primary under Voltage disturbances: ▪ A three phase voltage drop to zero for 0.2 s ▪ A voltage drop to 75% of nominal voltage for 1 s ▪ A voltage drop to 85% of nominal voltage for 60 s. ▪ The Contractor will be responsible for demonstrating under test conditions that this criteria is met. • Ambient temperatures of up to 50°C in full sun on to...
