A. SPECIFICATIONS FOR STS COMPLIANT INTEGRATED SINGLE-PHASE, 2-WIRE,
KEYPAD PREPAID MOUNT METERS
1.0 Introduction
The prepaid metering systems shall be used for metering of domestic, commercial and
industrial loads. All meters under these specifications shall comply with the requirements of
SANS 1524-1 and other internationally recognized standards. Single phase integrated
prepayment meters shall be designed and constructed in accordance with the requirements of SANS
1524-1-1 or any other internationally recognized standard.
2.0 Design and applications
The meters shall be designed to ensure convenience and security to both the utility and the
users. The meters shall therefore be designed in line with the under listed specifications.
2.1 STS compliant
The system shall be constructed basing on the Standard Transfer Specification (STS) open
standard, offering secure transfer of credit between the vending point and the meter.
2.2 Accreditation
The supplier and the products supplied shall be ISO certified.
2.3 High performance LCD
The meter shall incorporate a large LCD and display the remaining credit so as to help the
customer to manage energy consumption. The LCD shall also be able to display all inputs
entered into the meter keypad interface.
2.4 Tariff
The management system shall support multiple tariffs which shall allow the utility to allocate
different tariffs to different users at different times for example Commercial, Industrial,
Domestic and different times of Peak, off-peak and shoulder.
2.5 Low credit warning
The meter shall incorporate a low credit warning by means of a visible LCD icon, LED and
audible buzzer alarm when threshold is reached.
2.6 Power management control
The power supply shall be automatically disconnected when the credit is exhausted, on
current overload and in case of tamper. In the event of tamper, the meter shall only be reset
by an authorised utility agent with a unique tamper reset token.
2.7 Anti fraud function
The meter shall be designed to block fraudulent customers in order to reduce energy losses.
To achieve this, the meter shall support anti-tamper features such as; meter cover open,
terminal cover open, external magnetic fields, reverse energy, meter bypass, phase to
neutral line interchange and load earthing.
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2.8 Optical interface
The meter shall be supplied with an optical port and /or MC 171 communication port;
compliant with IEC 62056-21. This shall allow the utility to access information stored in the
meter and uploading information with a Hand Held Unit.
2.9 AMI Compatibility
All supplied meters should have AMI functionality.
2.10 Meter protection
The outer cover (casing) of the meter shall be transparent on its front side. This shall be for a
clear view of the meter terminals even from a distance. The meter shall have a circuit
breaker that shall be rated 60A which shall be mounted on its left hand side. The meter
terminals shall however be in position to withstand a current of more than 80A.
2.11 Weight of the meter
The total weight of a complete meter set (including its cover and circuit breaker) shall be
specified.
B. SPECIFICATIONS FOR THE STS SOFTWARE AND VENDING SYSTEM
3.0 Software support system
Alongside the Technical specifications, K.I.L will need the STS compliant vending Software
that will work on computers with Windows XP operating system, support SQL Database
Management, and Normal printers shall be used. The software shall comprise of a solution
complete to utility, customer and revenue management system based on:



Management System comprising of vending Servers.
Vending units
Communication connections using GPRS and/or ISDN.
3.1 Software Features
The system design shall incorporate the following features and applications.
 Reduced operational costs,
 Secure Data Transfer,
 Intuitive user interface ensuring ease of use (shall be user friendly),
 Support single and multiple/complex tariffs,
 Operator profile management and security,
 Flexible data reports,
 Scalable system.
3.2 Communication, data collection processing and output

The system shall be able to collect, store and process customer data from the meters
using in-built meter GPRS/CDMA/GSM or PLC or RF. The system shall be able to export
the data to excel spreadsheets and Microsoft word for further analysis.
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
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The interface shall be designed to incorporate standard windows drop-down menus and
self explaining shortcut icons so as to make the software user-friendly.
The system shall allow for addition of new customers and editing of existing ones.
Additionally, the system shall be able to do the following:
 Meter data management
- Customer details (Serial number, Name, location),
- Tariff information,
- Customer monthly purchases,
- Customer Type (Domestic, Commercial or Industrial),
- Transformer details (Serial number, type and location),
- Line /Phase location,
- Meter parameters.
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Delivering data to the billing system Server on subsequent purchases,
Customer behavior pattern,
Load profile analysis,
Storage Management.
3.3 Vending Systems
The vending units shall be able to:
 Provide real time power transaction processing,
 Manage single phase, three phase and bulk purchases of energy,
 Generate electricity tokens without duplication,
 Provide customer information registration and storage,
 Carry out account cancellation,
 Meter reading details,
 Meter operation parameters modification (modify parameters including pre-alarm
threshold, alarm threshold, overdraft threshold and credit threshold, load threshold),
 Tamper events treatment,
 Reverse use and overloads,
 Data security management,
 Residual value transfer in case of meter getting faulty or burnt with customer credit,
 Delete repetitive purchases,
 Do any other activity that shall enable data management and operation flexible.
3.4 Protection and data recovery
The bidder shall be able to provide hardware and software backup, protection and
redundancy for business continuity in the event of a disaster.
3.5 Inter operability
The STS Software shall be able to work with other meters as may be provided by other
suppliers.
3.6 Reporting
The system should be able to provide a variety of reports which shall not be limited to:
 Automated customer reports,
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Customer history,
End of shift sales batch,
Banking batch.
3.7 Training
The bidder shall be required to provide on-site training to meter installers, management
system operators and vending unit operators. Additionally, the bidder shall be required to
provide the software, upgrades and associated protection for the hoisted infrastructure and
online assistance to the operators for need to clarify some information.
TECHNICAL SPECIFICATIONS
STS COMPLIANT, INTEGRATED SINGLE PHASE KEYPAD PREPAID MOUNT METERS
No
Item
A.1
Standards
A.2
A.3
A.4
A.5
A.6
A.7
A.8
A.9
A.10
A.11
A.12
A.13
A.14
A.15
A.16
A.17
A.18
A.19
A.20
KIL’s Requirements
IEC 62052-11, IEC 62053-21, IEC62053-31,
IEC 62056-21, IEC 62055-41, IEC 62055-51,
STS, SANS 1524-1
Meter type
Integrated Single-Phase, 2-wire, keypad
prepaid mount meter. Complete with integral
earth leakage, over current and short-circuit
protection. Direct connection via a Circuit
Breaker of 60A.
Rated Voltage
240V±10%
Accuracy Class
Class 1
Frequency
50Hz
Basic Current
10A
Maximum Current
80A (lower limit programmable)
Accurate meter range
0.05Ib to 1.25Imax in accordance to IEC
61036
Burden
2W/10VA
Over voltage withstand
440V for 48 hours
Protection class
IP54
Disconnection device
Two pole-ganged circuit breaker (rated 60A)
with overload and short-circuit protection
(2.5kA) in the live pole.
Operating temperature
0-55oC
Humidity
operating 95% RH
range
Low credit alarm
LED, Buzzer and LCD icon
General usage
Credit store with decrement-on-usage.
User interface/Display LCD/LED
display,
12
digit
keypad
information
International
standard
layout
including
“information key” and “backspace” key to
correct invalid entries.
Credit entry mechanism Key pad, encrypted numbers
Encryption algorithms
STS (Standard Transfer Specifications)
compliant
LCD Display
The following information shall be displayed:
 Remaining credit in kWh,
 Token acceptance or rejection (Ok/Used/
Duplicate/invalid token),
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Bidder’s
offer

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A.21 LED Indication
A.22
A.23
A.24
A.25
A.26
Low credit indication warning (minimum
threshold),
Tamper status,
Consumption indicator,
All purchase energy (cumulative) kWh,
Supply status.

Instantaneous power consumption (rate
1000 impulses/KWh)
 Temper status
Disconnection Device/ Internal single pole latch relay to 80 Amps.
Contactor
Compatible with IEC 62055-31
Impulse
voltage 6kV and lightening protection according to IEC
withstand
62053-21.
Terminals and terminal  Fire
resistant,
UV
stabilised
block
polycarbonate.
 Terminals and terminal block shall
withstand a current of more than 80 A.
Terminal arrangement
Connection diagram should be provided on
meter casing.
Terminal cover
 Thermal plastic with independent seal.
Terminal cover should be transparent for a
clear view of the terminals at a distance.

A.27
A.28
A.29
A.30
A.31
A.32
The seal should cover the terminals and
access to the terminals such that access
is not possible without breaking the seal.
Meter case material
UV stable Reinforced polycarbonate that
should be transparent on its front side for a
clear view of the meter and its terminals at a
distance.
Meter mounting and Two mounting screws, top and bottom and in
fixing
accordance to IEC and BS standards
Reverse energy
Meter shall disconnect completely in case of
reverse detection, bidirectional power flow
credit decrement and cumulative register
increment provisions. Meter shall have a
reverse energy detection alarm.
Starting current
≤ 0.004Ib (typically 0.002Ib at 240V)
Power threshold
4.8 W (approximately 20mA at 240V and
PF=1)
Maintenance free period 10-15 years
A.33 Tamper
detection
and
fraud 

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Electronic system and Mechanical seals.
Presence of seal screw plug on the front
of the meter.
Presence of an anti tamper sensor on the
meter for preventing meter box opening.
Load disconnection from power when the
active part of the meter is removed from
the passive meter box.
Display of tamper status by means of LCD
icons.
Reconnection exclusively by means of
engineering token issued by the vending
and management system.

A.34 External
Interface/
Communication
A.36 Emergency
credit recovery
A.37 Data transfer
A.38 Maintenance Tool
A.39 Accessories
A.40 Key pad life time
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For meter to base; Screws with plastic
anti-tamper inserts crimped wire seals.
 Internal electronics shall be Factory
sealed with plastic anti-tamper plugs.
 Data can be read with an external device
(Hand Held Unit) if the meter is faulty, or
LCD cannot display
 Optical port with EC 62056-21,
Meter shall have a provision for the
recovery/retrieval of credit from the meter
when it is off or faulty.
STS compliant, Numeric token
 Optical data extraction tool
 MC 171 data extractor
 Fixing screws
 Security seal and wire screws
 Dispenser cards with meter numbers
More than one million operations per key