IDF, RDF, ADF, and CDF are meter read remarks used by the electricity department to identify issues related to defective meters.
Here, DF stands for Defective.
Full Forms:
- IDF – Identified Defective
- RDF – Reading Defective
- ADF – Appear Defective
- CDF – Ceiling Defective
Lets understand one by one
1. IDF (Identified Defective)
This remark is entered manually by the meter reader when they identify that the meter is defective and needs replacement before the next billing cycle. Examples:
- Meter has no display
- Meter burnt due to short circuit
2. RDF (Reading Defective)
This remark is auto-generated by the billing system when the previous reading is higher than the current reading.
In such cases, the licensee must investigate:
- If the meter is OK but reading was punched incorrectly, the bill needs revision.
- If the meter is actually defective and showing reverse reading, it needs replacement.
3. ADF (Appear Defective)
This remark is auto-generated when there is no change between the previous and current readings.
Possible causes:
- No electricity usage for that month.
- Internal fault in the meter causing reading to stop.
Such meters should be checked on-site and replaced if required.
Note: UPPCL has currently dropped this remark, and bill gets generated OK with 0 consumption
4. CDF (Ceiling Defective)
The term Ceiling means limit or boundary. As per norms, Ceiling is defined as 800 units/kW/month. If consumption exceeds this limit, the billing system automatically marks CDF, and the licensee must inspect the site to verify:
- Whether the consumer is using load higher than sanctioned load.
- Whether the meter reading was manipulated earlier.
- Whether the meter is defective and showing abnormal jump in reading.
Note:
Why Ceiling Limit is 800 kWh/kW/Month
Technically, a 1 kW load can consume a maximum of 720 kWh/month (1 kW × 24 h × 30 days). Considering a few extra days in some billing cycles, the limit was rounded to 800 kWh/kW/month.
If consumption exceeds this, it usually indicates a defective meter, excess load use, or abnormal reading.
Though DISCOMs have recently raised the limit to 1500 kWh/kW/month to avoid unnecessary CEIL billing, the earlier 800 kWh limit was technically justified.
