When a commercial property loses power, the main breaker and the local substation are often blamed before anyone has established where the supply stopped. A dark building can result from a utility network interruption, a service or metering issue, operation of the property main protective device, a downstream distribution fault, an emergency control, backup-power behaviour or planned work. Safe triage does not diagnose those possibilities from a distance; it collects observations that route the incident to the correct authorised party.
This Gauteng guide is for facilities managers, trustees, managing agents, security teams and business occupants. It explains what can be checked without opening electrical equipment, how neighbouring properties and common areas change the first hypothesis, what information City Power or Eskom needs, and what an electrician may test on the property side. It does not authorise anyone to operate sealed utility equipment, remove covers, bypass protection or repeatedly reset a main breaker.
01
Start with the supply boundary, not the suspected component
Electricity reaches a commercial property through a chain of assets. Depending on the site, that chain can include utility network equipment, a local transformer or substation, service cables, metering and control equipment, the point of supply, the property main switchboard, downstream boards and final circuits. Different parties may own, operate or be authorised to access different parts. A symptom at the tenant desk does not identify which link failed.
The first incident record should state the exact property, time, weather, planned-work notices, areas affected and the last known normal condition. It should also identify whether the property is supplied directly by Eskom, City Power or another municipality. Using the wrong reporting channel can delay a response, while calling an electrician to operate utility equipment creates a responsibility and safety problem.
Name the affected boundary precisely
Instead of saying the whole site is dead, record whether external signage, common areas, lifts, gates, tenant floors, server rooms, landlord plant and neighbouring buildings have power. A site with a generator or inverter can appear partly energised even when normal utility supply is absent. The operating source must therefore be identified before anyone assumes the main incomer is healthy.
Keep utility and private equipment separate
Meter seals, street kiosks, transformers, substations and many service devices belong to or are controlled by the utility. Occupants and private contractors must not tamper with them. The property team should report visible damage and stay clear. Property-side work begins only at an authorised boundary and within the competence and access permissions of the person attending.
02
Make only safe, external observations
Look from a safe position for normal indicator lights, displayed alarms, smoke, smell, water, unusual sound, visible damage and the position of devices that occupants are authorised to view. Do not remove a distribution-board cover, defeat an interlock or reach into a cabinet. Do not touch metalwork when there is evidence of heat, arcing, water ingress or damaged conductors.
If there is smoke, fire, a fallen conductor, exposed live parts, a damaged pole or transformer, or anyone has received an electric shock, treat the event as an emergency. Keep people away, contact the relevant emergency and utility channels, and do not attempt restoration. Supply interruption is inconvenient; an unsafe attempt to restore it can turn the event into a serious injury or fire.
Use eyes and records, not improvised testing
A phone photograph taken from a safe public or authorised position can preserve alarm text and device indication. A building-management or backup-power event log may also help. Plugging in homemade testers, opening panels or probing incoming conductors is not triage. Electrical measurements at the main board require appropriate instruments, protective equipment, safe procedures and a competent person.
03
Check neighbouring properties and common areas
Neighbouring properties are useful evidence because they may share part of the upstream network. If an adjacent building, street lighting and the local commercial block all lost supply at the same time, a utility-side interruption becomes more plausible. It is still not proof: nearby properties can have different feeders, phases, transformers or backup systems. Record the observation without overstating it.
Inside a sectional-title, office park or shopping property, compare common areas with the affected tenant. If the gate, lifts, corridor lighting and several tenants are affected, investigate the shared supply path and utility status. If only one suite or floor is dark while common services remain normal, the first property-side diagnostic point may move downstream toward that tenant distribution path.
Ask whether backup power is masking the outage
A neighbouring office may appear operational because a generator, solar inverter or UPS is carrying selected loads. Ask whether normal utility supply is actually present and whether high-power loads are available. On your property, record which circuits remain supplied and from which source. Partial backup operation must not be mistaken for evidence that the utility incomer is healthy.
Avoid crowd-sourced diagnosis
Security groups and neighbourhood chats can identify the footprint of an outage, but messages such as substation tripped are often assumptions. Use them as leads, then verify against official utility notices or fault references. Preserve the time and affected streets or properties rather than circulating a technical cause that has not been confirmed.
04
Recognise clues that favour a utility-side interruption
A wider geographic footprint, loss of utility supply at several independent properties, official outage notices, damaged street infrastructure or a utility fault reference all support escalation to the network operator. Loss across all phases at the point of supply may also support that path, but confirming voltage at the supply boundary is electrical testing and must be performed only by an authorised competent person.
Planned maintenance, load curtailment and local network faults can produce similar occupant symptoms even though their causes and restoration processes differ. Facilities teams should record notice numbers, published schedules and the time actual supply changed. Do not claim that a substation operated unless the utility confirms it or credible technical evidence establishes that cause.
Log the fault with the correct utility
City Power provides fault-logging channels and publishes a call-centre number and escalation number. Eskom customers can report a power interruption through Alfred, WhatsApp or the contact centre. Direct Eskom tools are for customers supplied by Eskom, not every property in Gauteng. Record the utility reference number and the account or meter information used.
- City Power fault logging and regional contacts — Official City Power page listing fault-logging contact and escalation channels.
- Eskom customer service and power-fault reporting — Official Eskom customer-service page with reporting channels and the information customers should have ready.
- Eskom Alfred self-service channels — Official Eskom explanation of fault logging, reference numbers and follow-up through Alfred.
05
Recognise clues that favour a property-side fault
If neighbouring properties and common services have normal supply, only one board or area is affected, a property protective device has visibly operated, or the outage followed internal work or a specific load event, the evidence may favour a fault on the property side. That still does not identify the failed circuit or prove that the utility supply is healthy on every phase.
Heat, burning odour, buzzing, visible damage, water ingress or repeated operation of protection strengthens the need for a controlled electrical investigation. Do not keep resetting the main breaker. Protective devices operate for a reason, and repeated closing can expose equipment to further fault energy. Secure the area and report the sequence of events to the attending electrician.
A partial outage is diagnostically useful
Record which floors, phases or load groups remain available. Loss of selected circuits may indicate a downstream protective operation, failed component, control issue or phase-related supply problem. The distinction cannot be made safely from a list alone, but the pattern tells the electrician where to begin measurements and what diagrams or keys to request.
Recent changes belong in the brief
New air-conditioning equipment, tenant alterations, generator servicing, inverter work, water ingress, excavation and distribution-board maintenance can change the diagnostic path. State what changed and who performed it. Avoid deciding that the last contractor caused the outage; timing is evidence to investigate, not proof of responsibility.
06
Understand why a main breaker may operate
A main protective device may operate because of overcurrent, a short circuit, an earth fault through associated protection, an undervoltage or shunt-trip control, interlocking, emergency switching, internal device condition or coordination with downstream protection. Large motors, transformers and restored loads can introduce starting or inrush conditions that also need to be considered. The handle position alone does not establish the cause.
Where a breaker has trip indication or an electronic protection unit, the displayed cause and event record should be preserved before authorised reset or testing. Some devices require a specific reset sequence. Manufacturer instructions, the single-line diagram and the protection study may be necessary. An untrained person should not use the main breaker as a diagnostic switch.
One reset is not a universal rule
Advice that every breaker may be reset once is unsafe because equipment, access and incident conditions differ. A facilities procedure should state who is authorised to operate each device and under what verified conditions. Where the cause is unknown, a main device has operated, or warning signs exist, assessment before re-energisation is the safer route.
Protection coordination affects what trips first
Ideally, a downstream fault is cleared by the nearest suitable protective device so that unaffected areas remain supplied. Actual selectivity depends on device settings, fault current, time-current behaviour and the installation design. If the main device repeatedly operates for downstream events, the diagnostic report should consider settings and coordination rather than simply replacing the breaker.
07
Use substation language carefully
A substation transforms, switches or distributes electrical power within the utility network or a private site. A reported substation trip can refer to many different protection or switching events, and the utility may isolate equipment while locating the fault. Occupants cannot determine those details from the sound of an outage or the fact that several streets are dark.
Some large properties own or operate private transformers and medium-voltage equipment beyond the normal competence and authorisation of a low-voltage service contractor. Site documentation should identify the appointed competent persons and emergency procedures for that equipment. No one should enter a substation room, cross a barrier or operate medium-voltage equipment merely because the building is without power.
Report visible hazards without approaching
Smoke, fire, damaged fencing, fallen conductors, arcing or oil leakage near utility equipment should be reported from a safe distance. Do not approach for a better photograph. Provide the location, pole or equipment number if it can be read safely, the time and the nature of the hazard. Keep the public away until the responsible authority makes the area safe.
08
Treat phase loss and abnormal voltage as urgent evidence
A three-phase building can lose one phase or experience abnormal voltage while some lights and plug circuits remain operational. Motors, lifts, pumps, HVAC plant and other three-phase equipment may be damaged or unable to start correctly. Flickering, unusual brightness, equipment alarms or simultaneous failures across different load groups should be recorded and escalated; occupants should not keep trying equipment to see what works.
The origin could lie in the utility service, a main connection, protection, switchgear or downstream distribution. Proper diagnosis requires voltage and continuity measurements at controlled points, together with the single-line diagram and safe isolation. If abnormal supply is suspected, switch-off decisions should follow the site emergency procedure and be made by an authorised competent person.
Protect motors from repeated restart attempts
Automatic controls may repeatedly attempt to restart plant after supply changes. Facilities staff should know how the approved emergency procedure handles lifts, pumps, chillers, compressors and server cooling. Repeated attempts during phase loss or unstable voltage can increase damage. The response should prioritise safe isolation and diagnosis, not rapid cycling.
09
Include generators, inverters and UPS systems in the triage
Backup power changes the symptoms of an outage. A generator may fail to start, start but not connect, connect only essential loads, or be blocked by a control alarm. An inverter may carry lights and computers while lifts and HVAC remain off. A UPS may support servers for minutes even though every normal supply source is unavailable. Record source indicators and supported circuits without opening equipment.
Backfeed prevention, changeover arrangements, neutral configuration, protection and earthing all affect safe operation. No temporary lead or improvised connection should be used to energise a dead board. If backup power behaves differently from the approved design, isolate the issue within the authorised operating procedure and ask the responsible contractor to investigate.
Use event logs before clearing alarms
Generator, inverter, automatic-transfer and UPS controllers often retain event information. Photograph or export the log before alarms are cleared when the site procedure permits. Record fuel status, maintenance work and the loads that were available. The sequence can show whether utility loss, a transfer inhibition or an internal protection event occurred first.
Confirm restoration before returning all load
When normal supply returns, uncontrolled simultaneous restart can create high demand and inrush. Critical buildings should have a documented restoration sequence for plant and tenant loads. An electrician can assess the distribution condition, while facilities teams coordinate operational restart. The utility restoration message alone does not prove every property circuit is ready.
10
Know what a property-side electrician may diagnose
A structured diagnostic sequence begins with the incident brief, hazards, supply responsibility and single-line diagram. The electrician identifies safe isolation points, checks authorised indications, confirms incoming and outgoing conditions with suitable instruments, reviews protective-device status and narrows the fault boundary. Tests are chosen from evidence; circuits are not randomly disconnected until the problem disappears.
The result should state what was reported, what was observed, where measurements were made, what the results show, any limitations, the immediate safe condition and the recommended next action. If the evidence points upstream, the report can support the utility escalation. If the fault is internal, it can define isolation, repair, further testing and return-to-service requirements.
Separate restoration from root-cause work
Emergency work may restore safe essential service without completing the permanent repair or identifying every contributing factor. The close-out should distinguish temporary isolation, service restored, permanent remedial scope and preventive recommendations. This prevents a successful restart from being mistaken for a completed investigation.
Preserve testable evidence
Do not discard a failed component, clear every log or alter protection settings before the relevant evidence is recorded. Photographs, device identifiers, settings, event times and test results can help later review. Evidence must still be handled safely and within property, insurer and manufacturer requirements.
11
Give the utility or electrician a complete first report
For a utility report, provide the customer or account details, meter information, exact address, contact person, time supply was lost, affected footprint, visible hazards and any published notice. Eskom specifically asks customers to have account, meter, pole, address and contact details ready. City Power and other municipalities may use different fields, so follow the current official channel.
For an electrician, add the main and downstream areas affected, backup-power state, protection indications, recent work, unusual smell or sound, water exposure, plant that was running, site access, key holder and shutdown constraints. Include the utility reference number if a fault has already been logged. A complete brief reduces duplicated checks and helps the attending person bring suitable instruments and protective equipment.
Use a simple incident timeline
Record events in time order: normal operation, first symptom, alarms, equipment operation, utility report, authorised switching, technician arrival, tests, restoration and follow-up. Use exact times where possible. A timeline is especially valuable when automatic transfer and multiple protective devices operate within seconds of each other.
- Property, supply authority, account or meter reference and responsible contact.
- Time, weather, planned-work notice and geographic footprint.
- Areas and essential systems with and without supply.
- Visible indications, alarms and hazards observed without opening equipment.
- Backup-power state and recent electrical or building work.
- Utility fault reference, actions already taken and current safe condition.
12
Route the incident by service area without changing the diagnosis
The diagnostic principles remain the same across Gauteng, while the supply authority, site access and building pattern change. A Sandton high-rise may involve landlord switchrooms and tenant floors; a Midrand office park may have shared private distribution; a Centurion site may be supplied through different municipal or Eskom arrangements. Confirm the utility shown on the account and at the authorised property record.
Wesslink regional hubs provide local service context for Sandton, Randburg, Midrand, Centurion and Roodepoort. They do not replace the fault-finding owner page and they do not imply that every outage is internal. Use the utility for verified network-side incidents and use a qualified electrician for authorised property-side diagnosis when safe observations point inward or remain inconclusive.
Keep the search intent informational
This page explains triage and responsibility boundaries. It is not designed as another generic location service page. The regional links help a property manager confirm area context after the diagnostic path has been understood, while the fault-finding service remains the primary route for investigation inside the property.
- Sandton electrical service area — Regional context for Sandton properties.
- Randburg electrical service area — Regional context for Randburg properties.
- Midrand electrical service area — Regional context for Midrand properties.
- Centurion electrical service area — Regional context for Centurion properties.
- Roodepoort electrical service area — Regional context for Roodepoort properties.
- South African Electrical Installation Regulations — Official Department of Employment and Labour regulations governing installation work, inspection, testing and certification.
13
Review the event after supply is restored
Restoration closes the interruption but not necessarily the incident. Confirm that all phases and essential systems returned normally, backup equipment transferred back as designed, alarms were cleared for a known reason and no board shows heat, odour or damage. Record the final utility or electrician reference and the time each operational area was returned.
Recurring outages deserve a pattern review. Compare utility references, main-breaker events, weather, plant operation, maintenance history and affected areas. The pattern may support a network escalation, a protection-coordination study, board repair, load assessment or backup-power change. A decision-ready history is more valuable than a folder of messages that simply say power off again.
Close actions by owner and deadline
Assign each action to the utility, landlord, body corporate, tenant, electrician, generator contractor or facilities team as appropriate. State the evidence required for close-out and the operating restriction until it is complete. This prevents a temporary workaround from remaining undocumented after everyone returns to normal work.
FAQ
Questions readers also ask
How can I tell whether an outage is from the substation or my building?
Check the affected footprint, neighbouring properties, common areas, official utility notices and safe device indications. These clues route the incident but do not prove the cause. Utility confirmation or property-side electrical testing may still be needed.
Should I reset the main breaker after a power failure?
Do not assume a reset is safe. Follow the site procedure and device instructions. If the cause is unknown, a main device operated, or there is heat, smell, sound, water or damage, keep clear and arrange assessment before re-energisation.
Can one property be off while the neighbours still have power?
Yes. Properties can be on different feeders or phases, use backup power, or have separate service and internal faults. Neighbour supply is useful evidence, not a final diagnosis.
What should I report to City Power or Eskom?
Use the correct official channel and provide the exact address, account or meter information, contact details, time, affected footprint and visible hazards. Keep the fault reference number for follow-up and for the electrician if property-side diagnosis is also required.
Why do some circuits work during a building outage?
They may be supplied by a generator, inverter or UPS, or the interruption may affect only a phase, feeder or downstream board. Record which loads work and the indicated source without opening equipment.
What will an electrician test during an unclear outage?
The sequence depends on the site, but may include authorised checks of incoming and outgoing conditions, protection status, phase availability, circuit isolation and relevant continuity or insulation evidence. The electrician should document the fault boundary, limitations and next action.