The authority comments that keep coming back on UAE electrical submittals

By Eng. Mannan Maqsood, Electrical EngineerPublished 7 November 20264 min read

Anyone who has submitted electrical drawings to a UAE utility knows the feeling: the package comes back with a list of comments, half of which you have seen on the last three projects. The details differ between DEWA in Dubai, ADDC and AADC in Abu Dhabi, SEWA in Sharjah and EtihadWE in the Northern Emirates, and each authority updates its regulations and circulars. But the themes behind the comments are remarkably consistent. This article groups them so you can check your package before it goes in. Always confirm the exact requirement against the current regulations and circulars of the authority you are submitting to.

1. Numbers that do not match across documents

This is the most common reason for a return, and the easiest to avoid. The connected load on the load schedule does not match the summary sheet, the maximum demand on the application form is different from the SLD, or the transformer rating on the substation drawing is not the one in the calculation.

Check: produce one load summary and copy every figure from it: connected load, demand factors, maximum demand in kW and kVA, power factor, number of transformers. Then search every drawing and form for each number. If a figure changes, change it everywhere in the same revision.

2. Diversity and demand factors not as the authority requires

Each authority publishes its own approach to diversity for residential units, commercial areas, chillers, lifts and other loads. Applying textbook diversity, or the diversity from a previous project in another emirate, changes the maximum demand and therefore the number of transformers and the size of the supply.

Check: state the source of every demand factor on the load summary, and use the factors in the regulations of the authority you are submitting to.

3. Load schedules that do not add up

Typical findings: phases badly unbalanced, totals that do not include spare ways, breaker ratings that do not match the cable sizes, missing RCD or ELCB protection on circuits where it is required, and DBs whose total load exceeds the rating of their incoming device.

Check: run every DB, SMDB and MDB schedule through a consistency check before the drawings are plotted. The Load Schedule Auditor reads Excel schedules and flags phase imbalance, breaker and cable mismatches and wrong totals.

4. Voltage drop not shown from the source

A voltage drop calculation for each cable on its own is not enough. The reviewer wants to see the drop from the point of supply to the furthest final circuit, compared with the limit in the regulations. Long risers in towers and long final circuits in villas and warehouses are where it usually exceeds the limit.

Check: add a cumulative voltage drop column to the cable schedule, from the LV panel or meter to each final board, and show the worst final circuit.

5. SLD missing ratings

Single line diagrams are returned for missing information more often than for wrong engineering. Breaker ratings without breaking capacity (kA), missing number of poles, cable sizes without the number of cores or the conductor material, no CT ratios on metering, no earthing arrangement, no indication of which loads are on standby supply.

Check: for every device on the SLD, show rating, poles, breaking capacity and type. For every cable, show size, cores, material, insulation and length. Show the fault level at the main board and confirm that every device downstream is rated for the fault current at its location.

6. Power factor correction

Authorities set a minimum power factor at the point of supply. Submissions are commented when the capacitor bank is missing, undersized, or not detuned in buildings with many variable speed drives and LED drivers, where harmonics can damage plain capacitors.

Check: show the kvar calculation, the target power factor required by the authority, the steps of the bank, and whether it is detuned (and at what percentage).

7. Earthing and protection details

Common comments: earth pit locations and resistance value not shown, main earthing terminal not detailed, no bonding of incoming services, protective conductor sizes not stated, and missing earth leakage protection on socket outlet and wet area circuits.

Check: include an earthing schematic with electrode resistance target, bonding connections and protective conductor sizes, and mark RCD protection on the DB schedules.

8. LV room, meter room and substation layout

Rooms that are too small, doors that open the wrong way or are too narrow for equipment removal, no ventilation detail, cables crossing other services, rooms below wet areas, or no access for utility staff. These comments are expensive because they affect the architecture.

Check: compare room layouts with the authority's standard layout drawings at concept stage, not after the architectural design is frozen.

9. Outdated forms and missing approvals

Using last year's application form, missing NOCs from other departments, an unsigned or unstamped drawing, or a material not on the approved list. These are administrative, but they still restart the clock.

Check: download the forms again for every new submission, and keep a short list of the approvals and stamps each authority asks for.

Before you press submit

1. One load summary, and every figure in the package matches it
2. Demand factors from the correct authority, with the source stated
3. Load schedules checked for balance, totals, breakers and cables
4. Cumulative voltage drop to the worst final circuit
5. SLD complete with ratings, kA, cable details and fault level
6. Power factor correction sized, and detuned where needed
7. Earthing and RCD protection shown
8. Room layouts compared with the authority standard drawings
9. Current forms, stamps, signatures and NOCs

Tools that help

The DEWA Design Tools & UAE Regs Reference collects the design checks used on UAE projects. The Authority Submission Pack Builder produces a consistent pack from one set of inputs, which removes the most common comment on this list: numbers that do not match.

Disclaimer. This article is general technical information for education only. It is not professional engineering, design, legal or safety advice for any specific project, and it does not replace the judgement of a qualified, registered engineer who has reviewed the actual installation. Worked examples and figures are illustrative and do not describe any identified project, client or site. Codes, authority requirements and product data change, so confirm every value against the edition that applies to your project, the authority having jurisdiction and the manufacturer's data. Any testing or work on live systems must be carried out only by competent, authorised people under the approved procedure. The views are the author's own and do not represent any employer, client or authority. To the extent permitted by law, the author, the editor and MEPVirtual accept no liability for any loss, damage or injury arising from the use of, or reliance on, this content. See the full disclaimer or report a correction.