Error Codes of STS Prepayment Meters

STS (Standard Transfer Specification) prepayment meters take digital medium as information exchange media. Users load in pre-purchased credit and then the meters take credit as their billing to realize the functions of active energy measuring and prepayment control and realize remote communication and remote control via module.
Local power companies or utilities use prepayment meters to avoid debts by charging power bills in advance. Additionally, prepayment smart meters with automatic reading function reduces cost of manual collecting meter data.
For end-customers, they can check their meter load in real time to use power reasonably. They can also recharge meters in any place and any time, instead of going to local power company to pay for.

CLOU STS Prepayment Meters

We have many STS prepayment meters, such as CL730S22 and CL710K22. You can also find more information about prepayment meters here.

Single Phase Meter CL710K22
Single Phase Meter CL710K22
Three Phase Meter CL730S22
Three Phase Meter CL730S22

Differences between TOKEN and Meter Numbers

TOKEN numbers and meter numbers are two totally different things.
According to the STS standard, a TOKEN has only complete 20 digits.
While CLOU STS meters have 11 digits. Other CLOU meters also have 12 digits.
The length of meter numbers is customized.
When you input a Token by which the prepayment meter can not work, the meter will show error codes. Specific reasons are cited one by one as below. If your meter equips an UIU (User Interface Unit), error codes also shows on its LCD.

Error Codes Shown on CLOU Prepayment Meter

CLOU regulates prepayment meter error codes in a certain statement according to the IEC62055-41 chapter 7.1. Almost all CLOU prepayment meters have the same error codes.
Here takes error codes shown on the CL730S22 three-phase meter as an example.

Meter Display Information

  • OPEN Any meter cover was opened
  • DISTU Magnetic disturbance detected
  • OVER PO Power exceeds the limit
  • VOL-OVER Voltage is over allowed threshold
  • CUR-OVER Current is over allowed threshold
  • CUR-UNB Current unbanlance occured
  • N-DST Neutral line is disturbed
  • CT-BYPAS Meter is bypassed
  • CT-OPEN Meter current circuit is open
  • VOL-UNB Voltage is unbalanced
  • HIGH-TMP Temperature too high
  • LOW-PF Power factor too low

UIU Display Information

  • ACCEPT TOKEN accepted
  • REJECT TOKEN rejected. The 20-digit TOKEN input is not generated from the designated platform.
  • OLD TOKEN expired
  • USED TOKEN used
  • FULL Overflow error. The credit register in the payment meter would overflow if the token were to be accepted; the token is not accepted.
  • OK Operation accepted
  • Err_01 Error in manufacturer code. The Manufacturer Code value in the Class 1 token does not match the Manufacturer Code value for the Decoder.
  • Err_02 Key expired error. The TID (Token Identifier) value as record in the token is larger than the KEN (Key Expiry Number)stored in the payment meter memory.
    Solution: First, please check your meter KEN value if it has expansion space or not; If the number is already maximum, shift the TID and change the Base Date in the energy selling system into “2014” option.
  • Err_03 DDTK (Decoder Default Transfer Key) error. The Decoder has a DDTK value in the DKR (Decoder Key Register): a Transfer Credit token may not be processed by the Meter Application Process in accordance with the values given in credit.
  • Err_04 Overflow error. The credit register in the payment meter would overflow if the token were to be accepted; the token is not accepted. (Some meter types are showing Err_04 instead of FULL).
  • Err_05 Key type error. The key may not be changed to this type in accordance with the key change rules.
  • Err_06 TOKEN format error. One or more data elements in the token does not comply with the required format for that element. That's say, to aviod this error, 20 digits of the TOKEN are correct and complete, and the TOKEN must be valid and unused. For example, the error shows when one only inputs 19 digits.
  • Err_07 TOKEN range error. One or more data elements in the token have a value that is outside the defined range of values defined in the application for that elements.
  • Err_08 TOKEN Function error. The particular function to execute the token is not available.
  • NULL Reserved

Troubleshooting to Pairing A UIU with A Meter

If something wrong happens while paring a UIU (User Interface Unit) with an energy meter, the following steps can be taken to initiate the UIU for troubleshooting.

  • Step1: Input "1593570" + "999" + "Enter" to initialize the UIU.
  • Step2: Input "1593570" + "11-digit meter number" + "Enter" to pair the meter with UIU.
  • Step3: Input "999" + "enter" to check the paired meter, and "12-digit address" will be displayed on the UIU.


So far, we have received a great number of comments about meter error codes and TOKEN. This article aims to at least provide a fundamental explanation to error codes.
For visitors who are finding information about them, wish this article can help you.
If you have more questions about error codes, just leave a comment below to discuss it.
Thank you for your reading and best wishes.

Editor's note: This article was originally published in November 2021 and has been updated for comprehensiveness.

88 Replies to “Error Codes of STS Prepayment Meters”
  1. Ciu display connection complete e.g 3units and terminal symbol ok .But no output on plc

    1. Thank you for reaching out with your query. It sounds like you've checked the display for eventually tamper indications or symbols, and everything seems in order there. If you're experiencing no output power and assuming there's no tamper indication, it's quite possible that the main MCCB (Moulded Case Circuit Breaker) has tripped. This could prevent power from reaching your home, even if the meter appears correctly connected. I would recommend checking your main MCCB, which is usually located near the energy meter, to ensure it hasn't tripped. If it has, resetting it should restore power. However, if the problem persists, it would be wise to consult a professional electrician to safely investigate the issue further.

  2. Good day! What causes the Clou meter to read in reverse, having a minus sign before the value of units? The meter has been working well for a while and all of a sudden it's recording in reverse

    1. Good day!
      When a STS prepaid meter reads in reverse, with a minus sign before the value of units, it typically indicates that the available units have been depleted, and the meter is now recording the consumed units as a negative value. Let me explain further:
      In most cases, the meter operates on a prepaid system, where each unit you use is deducted from the units that you have loaded onto the meter. The default behavior is that the meter disconnects when the units reach zero to prevent further consumption. However, some utilities provide an additional allowance known as an overdraft or emergency credit.
      If your utility has granted you an overdraft allowance, the meter will continue counting in the negative range once the loaded units are consumed. The amount of the overdraft units is predetermined by the utility and can vary. It's important to note that relying on the overdraft allowance for an extended period is not recommended, as the meter can disconnect at any time once the overdraft limit is reached.
      To resolve the issue, I suggest purchasing a new credit token as soon as possible to replenish the units on your meter. This will prevent any unexpected disconnection and ensure uninterrupted service. Additionally, it may be helpful to contact your utility and inquire about the specific details of your overdraft allowance, including any limitations or conditions associated with it.

  3. How can I reset my prepaid meter if the voltage is low. What do I do to increase the voltage

    1. An energy meter doesn't have the capability to manipulate the voltage level. If you are experiencing low voltage, it's essential to reach out to the utility or power company to report the issue. They have the authority and infrastructure to monitor and maintain the voltage levels in the electrical grid. They will be able to investigate and address any voltage-related concerns.

  4. Hello, I'll like to know if my meter indicates over vol. And the light trips off and on at intervals then displays over question is do I need to work on this issue or is it normal?
    Meanwhile I sent a message earlier but mistakenly wrote over volume instead of over vol.

    1. Thank you for your comment and question! It sounds like your meter is indicating over-voltage and causing the lights to trip off and on intermittently. This behavior is actually a result of the over-voltage protection feature in your meter.
      Over-voltage protection is designed to safeguard your electrical devices and appliances from excessive voltage levels, which can potentially cause damage. When the meter detects an over-voltage condition, it automatically interrupts the power supply to prevent any harm.
      However, if you are experiencing frequent tripping due to over-voltage, it is advisable to address the issue with your power company. They can assess the voltage levels in your region and make necessary adjustments to ensure a stable and safe electrical supply. It's also worth checking with your neighbors if they are facing similar issues, as it could indicate a broader voltage problem in the area.
      For more detailed information on over-voltage protection and related measures, you can refer to this article.

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