SPLIT PREPAID METERS IN BRITISH STANDARD (BS) HOUSINGS
The Cashpower Gemini is a single-
Prepaid Meters Features
- Split prepaid meters, significantly reducing the possibility of fraud and bypassing
- Compact meter design with British Standard layout
- Easy to install and ideal for new reticulation as well as retrofitting of credit meters with BS footprints
- Proven Cashpower keypad technology
- Programmable operating modes: Prepayment Meter
- Galvanically isolated communication to customer interface unit for consumer safety
- Tamper detection features
- Significant Reverse Energy (SRE) detection
- Programmable software power limit
- Commissioning / decommissioning feature
- Language independent user interface
- Optional large LCD and keypad at the meter
- Improved sealing against ingress of insects
- Easy to see diagnostic LED’s on the meter for status indication and communications
- High surge withstand capability for areas prone to lightning or other line surges
- SABS 1524 and IEC 62055-
- STS Compliant
Full Description of this Prepaid Meter
The Cashpower Gemini is a single-
Principle of Operation: Split Metering
The customer interface unit with its user-
The meter contains all critical metering, number decryption and load control functionality. It operates independently and is immune to any form of tampering on the customer interface unit.
The meter is usually installed in a secure, locked enclosure, typically a pavement kiosk or pole-
As an option, the meter can be supplied with its own LCD display and keypad which allows the utility to view important meter parameters without the need for an interrogation tool.
In Prepayment metering mode it functions as a normal prepaid meter. Credit tokens are purchased and entered into the meter via the customer interface unit keypad. On expiry of credit the load is disconnected and will only be re-
Energy Limiting Mode
This mode allows utilities to distribute a fixed, monthly allocation of energy to consumers. It encourages the rational use of energy without severely inconveniencing the consumer.
Operation is as follows:
Assume that a monthly energy allowance of 150kWh has been allocated to a consumer. The meter allocates this energy in regular, equal portions over the thirty-
Assuming that the consumer draws no power at all, the credit level will continue to increase. However, as soon as energy starts to be used, the credit level is proportionately decremented. If the rate at which energy is being used is less than the rate at which it is being incremented, the credit level will slowly continue to increase. If the rate at which energy is being used is greater than the rate at which it is being incremented, the credit level will slowly decrease. It is in the consumer’s interest to ensure that electricity is not wasted and that unnecessary appliances are turned off. By conserving energy, it will be possible to use it at a high rate for periods when required.
In the event of the consumer exceeding the allocated allowance (credit level reduced to zero), the load is disconnected. However, the next allocation of credit will be available within a very short period of time (15 seconds) and the supply of electricity restored. Providing the consumer takes immediate steps to disconnect unnecessary appliances, it will be possible to have at least basic services available e.g. lighting. With a 150kWh monthly allocation of energy, it will be possible to maintain a continuous load of 200W whilst still maintaining a positive credit balance.
User interaction with the meter and access to meter information (such as a low credit warning, energy consumption and load contactor status) is available using the customer interface’s keypad and large LCD display. The customer interface makes use of clear, language-
In addition, various audible tones are sounded under different conditions (e.g. Low Credit Alarm).
As an option, the meter can be supplied with a local keypad and LCD display. This allows the utility staff to inspect and update various parameters of the meter in the remote kiosk without having to gain access to the consumer’s house to access the customer interface unit.
Meter status and diagnostic indicators
The meter includes an LED status indicator. This allows a technician to view the state of the meter without the need for specialised interrogation tools or having to gain access to the consumer’s premises. Information such as tamper status, power limiting, commissioned status and credit status are available.
The meter also features a dedicated diagnostic LED for indicating the status of the customer interface unit communications. It can indicate the presence of “Open” or “Short” circuited communication lines. This is a valuable visual aid that assists the technician to validate the installation and determine probable fault types.
More detailed information and programming is achieved via the standard interrogation port at the rear of the meter.
As a standard feature, the Gemini family offers an IEC 62056-
The split configuration of Gemini meters significantly reduces the risk of tampering. The meter is installed in a remote, secure location and is mechanically sealed against tampering through the use of a factory-
In addition, the units are equipped with a terminal cover tamper sensor that will automatically disconnect the power to the load in the event of tampering.
The meter also has a feature allowing detection of Significant Reverse Energy (SRE). If the line and load wires are swapped during installation, the meter will continue to operate and decrement credit but can be factory programmed to tamper and disconnect the load should SRE be detected.
The Gemini family has the option of being supplied with a built in surge arrestor that is capable of sustaining up to 30kA during transients
Communication line protection
The communications interface can withstand voltage surges of 6kV, however it is recommended that one of the communication lines be earthed at the meter for additional protection.