If you manage a commercial site, control panels are the quiet decision makers in the background. They start and stop plant, manage pumps and fans, drive lighting controls, feed distribution boards and keep processes moving.
When they fail, the impact is rarely small. It might be a ventilation system stuck off on a warm day in Stratford, a pump trip in a plant room in Canary Wharf or a fault that takes out a retail back of house in Wembley.
A proper service visit is not just a quick look inside a cabinet. It is a structured maintenance routine that supports safety, reliability and documentation. HSE is clear that electrical equipment must be maintained to prevent danger and the type and frequency of checks depends on the equipment, the environment and previous results. (Maintaining electrical equipment safety)
This guide breaks down what a good service visit should include so you can compare contractors properly and build a retainer that reduces risk.
What counts as a control panel in commercial buildings
In day to day facilities terms, “control panel” can mean:
A BMS control panel for ventilation or air conditioning
A motor control centre (MCC) feeding pumps and fans
A plant control panel for boilers, chillers or heat pumps
A lighting control panel or relay panel
A power distribution panel or switchboard
In standards language, many of these assemblies fall under the umbrella of low voltage switchgear and control gear assemblies aligned with the IEC 61439 family. If you want a technical reference point, link the phrase IEC 61439 low voltage switchgear and control gear assemblies for a plain language overview.
Why control panels fail in real buildings
Most failures are not mysterious. They tend to come from:
Loose connections that gradually heat up
Overloading after tenant changes or equipment additions
Water ingress or condensation in plant rooms
Dust buildup restricting ventilation inside enclosures
Poor labelling leading to unsafe switching or slow fault finding
Control components wearing out such as contactors, relays and power supplies
Settings changes in BMS schedules after a refurbishment
This is why planned maintenance matters. HSE’s switchgear guidance is specifically aimed at owners and operators in industrial and commercial organisations and focuses on responsibilities for selection, use and maintenance. If you want a strong external reference for the phrase “switchgear maintenance”, use Keeping electrical switchgear safe (HSE HSG230).
What a proper service visit should cover
A good visit has three parts: preparation, safe inspection and usable reporting.
1) Preparation before anyone opens a panel
A professional contractor should ask for basics up front:
Site rules, access requirements and permit to work process if required
Whether shutdown is available or everything must stay live
Known issues, recent trips or nuisance alarms
Drawings, schematics or previous reports if you have them
Any critical operations windows for areas like Southwark, Westminster or Greenwich sites that operate late
If a service visit starts with no questions, it is usually a warning sign.
2) Safety first, especially around switchgear
If panels are live, the approach changes. You should expect the engineer to follow safe systems of work and to respect site rules.
HSE also provides a concise guide on electrical switchgear safety for users. For the phrase “electrical switchgear safety”, link to HSE electrical switchgear and safety.
3) Visual condition checks, inside and outside the enclosure
This is where many “services” are too light. A proper inspection checks:
External condition
Enclosure condition, locks and IP rating suitability for the environment
Signs of water ingress, corrosion or damage
Evidence of overheating such as discolouration around cable entries
Panel ventilation grills and fan filters where fitted
Internal condition
Signs of overheating on terminations and busbar areas
Loose or damaged cable management
Missing blanks or exposed live parts risk
Component condition including contactors, relays, power supplies and PLC modules
General cleanliness and dust accumulation
If your site follows SFG20 style maintenance regimes, distribution boards and panel assemblies often have structured inspection expectations. A useful reference point is the discussion around SFG20 distribution board compliance which highlights regular inspections and checks such as labelling verification and overheating identification.
4) Labelling and documentation checks
This is one of the easiest wins for reliability.
A proper service visit should confirm:
Circuit charts are present and accurate
Labels match reality
Isolation points are clearly identified
Emergency switching is clear and accessible where applicable
Poor labelling slows response and increases risk during faults.
5) Functional checks that match what the panel actually does
Not every panel needs the same tests. The checks should be tailored to the system.
Examples:
Verify control functions and auto manual selection for pumps and fans
Confirm safety interlocks operate correctly where applicable
Confirm alarm indicators and fault outputs are functioning
Check time schedules and setpoints where BMS controls are involved
Confirm panel fans and heaters operate if fitted
For a wider maintenance context, the IET has a useful overview on building basic electrical maintenance regimes for typical commercial premises. It is a solid external link for the phrase “electrical maintenance regime”. Use Setting up a basic electrical maintenance regime (IET).
6) Tightening and integrity checks where appropriate
Loose terminations are a common root cause of failures. A planned visit should include integrity checks appropriate to the equipment and risk.
Important note: do not expect a contractor to randomly torque critical connections without a method and without considering load conditions. A good contractor will explain what can be done live and what requires a planned shutdown.
7) Identifying overheating risk
Overheating is one of the most important risk indicators in control panels and distribution boards.
Even without advanced instrumentation, engineers should look for:
Discolouration
Melt marks on insulation
Smell of heat damage
Warped plastic parts
If you run a PPM programme, tracking these early signs prevents unplanned outages.
8) Housekeeping actions that prevent future faults
A proper visit often includes small actions that make a big difference:
Clean panel vents and filters
Improve cable management and strain relief
Replace missing blanks where safe to do so
Replace worn labels and tighten loose gland plates
These are not glamorous but they reduce risk.
What should be recorded after the visit
If you are paying for planned maintenance, you should receive documentation that helps you manage risk and budgets.
At minimum, a service report should include:
Assets checked and locations
Work completed and observations found
Photos of defects where useful
Defects list with priorities and recommended actions
Any parts that should be replaced soon
Any safety concerns that require urgent action
Confirmation of what was not done due to access or shutdown constraints
This is how the work becomes defensible during audits and procurement reviews.
How often should control panels be serviced
There is no one size answer. HSE’s position is that frequency depends on equipment, environment and previous findings. (Maintaining electrical equipment safety)
A practical approach many commercial portfolios use is:
Quarterly checks for higher risk panels or critical plant
Six monthly inspections for distribution style panels where your maintenance regime requires it
Annual planned shutdown service for deeper checks where possible
Extra visits after tenant changes, new equipment loads or repeated fault patterns
If you manage multiple properties across areas like Hammersmith, Ealing and Croydon, consistency matters. A standard template per site with room for risk adjustments is the easiest way to run a portfolio programme.
Common mistakes to avoid
A “service” that provides no written report
No asset register so nobody can prove what was checked
No remedials tracker so repeat issues never get closed out
One generic schedule applied to every building type
Ignoring environment factors like damp plant rooms or dusty back of house areas
A quick checklist for facilities managers
When appointing a contractor for panel maintenance, ask:
What does a standard service visit include for this type of panel
What parts do you inspect and what do you record
What requires shutdown and what can be done without disruption
How do you handle defects and follow up remedials
What reporting will I receive each month or quarter
If a contractor answers clearly, they are usually set up for a retainer relationship.
If you manage commercial premises in London and want control panel servicing that reduces downtime and produces documentation your team can actually use, Azure Electrical Ltd can help.
Get in touch with us and we will recommend a practical PPM schedule, clear reporting format and a remedials process that keeps your sites running smoothly.