What is a Load Demand Notification (LDN)?

A Load Demand Notification (LDN) is the formal declaration that an approved electrical consultant or contractor submits to the distribution utility, stating the project's estimated maximum electrical demand. Its purpose is to let the utility confirm that its local grid and primary substations have the capacity to host the project, reserve or allocate a transformer or substation, and, where needed, plan network reinforcement. In practice it is the first technical step in the connection sequence once the preliminary paperwork is in place.

In Abu Dhabi the notification is submitted to TAQA Distribution — the unified entity comprising Abu Dhabi Distribution Company (ADDC, covering Abu Dhabi City and Al Dhafra) and Al Ain Distribution Company (AADC, covering the Al Ain region). The unified "TAQA Distribution" brand began appearing on bills and branches from January 2025, while the ADDC and AADC names remain widely used in engineering practice, URLs, and Approved Vendor Lists. The sector regulator is the Department of Energy (DoE), Abu Dhabi, established under Law No. (11) of 2018, which replaced the Regulation & Supervision Bureau (RSB) and the Abu Dhabi Water & Electricity Authority (ADWEA). However, the technical rulebooks — notably the Electricity Wiring Regulations, originally issued under RSB — remain in force and are now administered by the DoE.

Note that the first load-declaration step in the Abu Dhabi workflow is often called the Preliminary Load Demand (PLD), which establishes the facility's allocated "power quota". The Load Demand Notification is the mechanism by which the declared maximum demand is formally registered with the utility.

When is an LDN required?

The notification is submitted at an early / preliminary design stage, before detailed design and construction, and before Single Line Diagram (SLD) approval. It is typically required in the following cases:

  • A new connection for a facility, building, or factory requiring permanent electrical supply.
  • A load upgrade for an existing facility where the new requirement exceeds the previously allocated quota.
  • Any material alteration to the electrical installation that changes the load profile appreciably.

The 10% rule: Under the applicable LDN documentation, any load increase exceeding 10% of the provisional connected load requires a new revision of the Load Demand Notification to be submitted for approval, and the previous revision becomes obsolete. Re-approval must be obtained before any construction begins, and the utility may require a modification to the substation layout at re-approval.

Who submits, and to whom?

The notification must be submitted by an approved electrical contractor or consultant — one holding a competency certificate / accreditation from the distribution utility. Under the Electricity Wiring Regulations, electrical installation works may only be carried out by a party assessed and approved by the Distribution Company and issued a Competency Certificate. A firm without this accreditation must partner with an approved firm that acts as the Engineer of Record and stamps the drawings. The recipient is the geographically relevant utility: ADDC for Abu Dhabi City and Al Dhafra, or AADC for Al Ain — both under TAQA Distribution.

Typical submission steps (the standard flow)

The following sequence is presented as a standard/typical flow rather than a guaranteed official procedure; details vary by project and location:

  • Pre-requisites and competency: trade licences, the site plan (Affection Plan) from the Municipality or the relevant free zone, the approved building permit, and engagement of an approved consultant/contractor.
  • Preliminary Load Demand (PLD) / LDN: declaring the estimated maximum demand and obtaining the allocated power quota or capacity confirmation.
  • Detailed design and SLD approval: the main incomer, distribution hierarchy, metering locations, and earthing arrangement, together with voltage-drop and short-circuit (fault-level) calculations.
  • Equipment and switchgear compliance: components selected from the Approved Vendor List (AVL), with LV panels from an approved panel builder.
  • e-NOC coordination: routing trench and cable drawings for clearances from the relevant authorities (water, telecom, roads, Civil Defence).
  • Permanent cable termination and site inspection: inspection of the internal wiring by the utility's inspector.
  • Energization, metering, and activation: submitting the Building Completion Certificate, settling connection fees and the security deposit, installing the tariff meter, and executing the grid connection.

Timeline: Industry guidance suggests that PLD and SLD approvals can take a few weeks when documentation is clean, but this can extend to several months with revision cycles and multi-authority clearances through e-NOC. Treat this as an indicative figure, not an official service-level agreement — confirm with TAQA Distribution.

How to calculate the maximum demand (methodology)

The core quantities an engineer must distinguish:

  • Connected Load: the arithmetic sum of the rated power (in kW) of every load, as if all ran simultaneously at full rating. It is the ceiling, never the real peak.
  • Maximum Demand: the greatest load the installation actually draws over a defined measurement interval (commonly 15 or 30 minutes). This is the headline figure declared and the value for which the utility reserves capacity.
  • Demand Factor: the ratio of maximum demand to connected load, always ≤ 1. Thus Maximum Demand = Connected Load × Demand Factor. Buildings typically fall in the 0.5–0.8 range depending on type.
  • Diversity Factor: the ratio of the sum of individual maximum demands of feeders/zones to the coincident maximum demand of the group, always ≥ 1 under the IEEE 141/241 convention; it reflects that feeders do not peak at the same instant. Note that IEC 60364/60439 instead use the terms "diversity factor" / "factor of simultaneity" to mean the ≤ 1 reduction multiplier, so the numeric convention is inverted under those standards — always check which convention your reference uses.
  • Coincidence / Simultaneity Factor: in the IEEE sense the reciprocal of the diversity factor, always ≤ 1, and it is the multiplier actually applied to reduce the summed loads. Important caution: some references conflate the two terms and, as noted above, conventions differ between standards — always check which direction the standard or the utility form uses, to avoid multiplying where you should divide.
  • Load Factor: the ratio of average load to maximum demand over a period; it is an operational metric of how efficiently capacity is used, does not reduce the declared maximum demand, and must not be conflated with the demand and diversity factors when sizing.

Bottom-up calculation chain (general approach):

  • Itemize the connected load per circuit/room/zone (lighting, small power/socket-outlets, HVAC, lifts, pumps, kitchen, external loads, spare ways).
  • Apply the appropriate demand factor to each load category: Zone Demand = Σ(Connected Load per category × Demand Factor per category). In a hot climate HVAC tends toward a factor near 1, whereas socket-outlet factors are much lower.
  • Aggregate zones/feeders up to the main board applying diversity between feeders: Board Maximum Demand = Σ(feeder demands) ÷ Diversity Factor (or × coincidence factor). Diversity is applied at every aggregation level, so the whole-building maximum demand is materially lower than the summed sub-demands.
  • Add a spare/reserve capacity margin for future expansion and to avoid re-application — the percentage is a design/utility choice (often cited around ~15–25% as general guidance) rather than a mandated constant.

kW to kVA conversion: Utilities reserve apparent power (kVA) because transformers and cables are rated in kVA. The relationship is: Apparent Power (kVA) = Real Power (kW) ÷ Power Factor. Where the power factor is unknown it is assumed for design purposes in the 0.8–0.9 lagging range, with many authorities requiring a minimum power factor (around 0.9) and power-factor-correction capacitors to avoid low-PF penalties — the exact minimum and its penalty regime are tariff-specific and must be verified with TAQA/ADDC.

Why accuracy matters commercially: over-estimating the maximum demand can force the developer to fund an unnecessary dedicated on-plot substation (extra capital cost); under-estimating causes breaker tripping and costly redesign when the utility later refuses additional allocation.

Documents required

The utility's LDN document checklist typically includes:

  • A statement of all types of electrical load (load declaration).
  • The premise/plot area (in square metres).
  • Owner's documents.
  • An updated site plan valid within 6 months.
  • The Single Line Diagram (SLD).
  • The Load Schedule.
  • The ground-floor electrical room layout.
  • An operational method statement (where required).
  • A copy of the proposed civil works layout.

In economic zones (such as KEZAD / AD Ports), an LDN NOC is issued from three documents — an application for the electrical LDN NOC, an electrical wiring diagram, and a table of electrical load details — which is then used to process the electricity connection application with TAQA Distribution. At the design-approval stage, further documents are added, such as: valid trade licences for owner and contractor, the Affection Plan, the approved building permit, voltage-drop and short-circuit calculations, transformer specifications, and Approved Vendor List (AVL) compliance documentation along with panel classifications and IP ratings.

Common reasons for rejection or delay

At the design-approval stage:

  • Non-compliance with the wiring regulations in cable sizing or load calculations.
  • Missing or incorrect voltage-drop or short-circuit calculations.
  • Equipment not on the Approved Vendor List (AVL).
  • Non-standard or unjustified demand/diversity factors versus building-type norms.

At the site-inspection stage:

  • Unauthorized on-site modifications to panel boards without revised approvals.
  • As-Built drawings not matching the physical installation.
  • Improper cable identification or incorrect phase colour coding.
  • Inadequate maintenance and operating clearances around switchgear.

Other common causes:

  • Inconsistent load figures between the SLD and the load schedule (a classic reject trigger).
  • Load exceeding the allocated/quota capacity, requiring network reinforcement or a dedicated substation.
  • Expired or stale documents (such as a site plan older than the 6-month validity window).
  • Missing consultant certification or use of a non-approved contractor.
  • Incomplete zone/area load breakdown or a missing electrical-room / civil-works layout.

Relationship to zone loads and the substation

The declared maximum demand (in kVA) drives the required transformer rating; the engineer selects the next standard size above (maximum demand + spare margin), typically keeping continuous loading around ~75–85% of the nameplate rating as general guidance, to allow for growth and thermal headroom. When the declared demand exceeds the capacity available to the plot from the existing network, the utility may require a dedicated on-plot substation (on a plot/room provided by the developer) rather than a connection from the network or a distribution kiosk.

Accuracy caution: There is no confirmed universal threshold (in kVA/kW) that mandates a dedicated substation or a particular voltage level (LV 415V versus MV 11kV/22kV) once exceeded; the threshold varies with location, available capacity, and existing infrastructure, and must be confirmed with TAQA/ADDC — a number must not be assumed. Likewise, connection fees and security deposits are settled later at energization, per the utility's current tariff schedule; do not rely on unverified figures.

Frequently Asked Questions

What is the difference between connected load and maximum demand?

Connected load is the arithmetic sum of the rated power of every load as if all ran at full rating simultaneously — a theoretical ceiling that is rarely reached. Maximum demand is the greatest load the installation actually draws over a defined measurement interval, and it is the figure declared in the notification and the value for which the utility reserves capacity. The demand factor links them: Maximum Demand = Connected Load × Demand Factor.

Who is the LDN submitted to in Abu Dhabi?

It is submitted to the geographically relevant distribution utility — ADDC for Abu Dhabi City and Al Dhafra, or AADC for Al Ain — both now operating under the unified TAQA Distribution brand. Submission and drawing stamping must be handled by a consultant or electrical contractor approved by the utility; otherwise an approved firm must be engaged to act as Engineer of Record.

When must a new revision of the LDN be submitted?

When a load increase exceeds 10% of the provisional connected load, a new revision of the Load Demand Notification must be submitted for approval, and the previous revision becomes obsolete. Re-approval must be obtained before any construction begins, and the utility may require a substation-layout modification at re-approval.

What is the difference between diversity factor and coincidence factor?

Under the IEEE convention the diversity factor equals the sum of individual maximum demands divided by the coincident maximum demand, and is always greater than one; the coincidence (simultaneity) factor is its reciprocal, is always less than one, and is the multiplier actually applied to reduce the summed loads. However, IEC 60364/60439 use "diversity factor" / "factor of simultaneity" to mean the ≤ 1 reduction factor, i.e. the inverse convention. To avoid error, define the direction of the factor (greater than 1 or less than 1) according to the standard or utility form rather than relying on the label alone.

Is there a specific kVA threshold that mandates a dedicated substation?

There is no confirmed universal numeric threshold. The need for a dedicated on-plot substation arises when the declared demand exceeds the capacity available to the plot from the existing network, and this threshold varies with location, infrastructure, and available capacity. It must be confirmed directly with TAQA/ADDC, without assuming figures.

How long does LDN approval take?

Industry guidance indicates that PLD and SLD approvals can take a few weeks when documentation is clean, and can extend to several months with revision cycles and multi-authority clearances through e-NOC. This is an indicative figure, not an official service-level agreement, and is best confirmed with TAQA Distribution.