ELECTRICAL SAFETY WHEN WORKING ON ELEVATORS
INSTRUCTION FOR WORKING ON ELEVATOR
This general instruction is valid for installation, servicing and modernization work done on elevators. It describes safe working procedures for preventing electric shock and other possible hazards from unwanted movement of equipment to yourself and others when working on elevators. Read and follow all related instructions and comply with your local safety codes and rules.
Electrical work on elevators may be done by authorized persons only. Where more than one person is working on an installation, the responsibilities and tasks for electrical safety should be clarified by the supervisor before the work is started.
Do not work on live equipment unless it is absolutely necessary (e.g. fault finding, fine tuning, etc.) If necessary a standard hazard and risk assessment, (refer to local procedures), should be made to define when to work live and when to isolate.
All persons working on the equipment are to attach and remove their own tag and, where possible, lock.
TOOLS AND SAFETY EQUIPMENT
Ensure that you have the necessary tools and equipment to complete your work tasks safely.
Use only approved insulated tools which are in a serviceable condition. Electrical test instruments must comply with local regulations and must be regularly tested in accordance with your local unit procedures.
Safety equipment
Tools, equipment and devices shall comply with the requirements of relevant European, national or International standards where these exist. Tools, equipment and devices must be used in accordance with the instructions and/or guidance provided by the manufacturer or supplier.
Examples of tools, equipment and devices:
SAFETY PRECAUTIONS
Familiarize yourself with the site and the building representatives
Get familiar with the working practices and the safety procedures of the worksite.
To ensure your safety, liaison with the site agent/builder/building owner or his representative is recommended especially where single man working is involved. Tell the building/site representative where you are working and when. If possible, ensure that a responsible person periodically monitors your welfare.
Avoid working in a building that is otherwise unoccupied.
Working area
Be aware of all the electrical risks, (including other non-elevator equipment), in the working area. These should be minimized by guarding, (temporary or permanent). If this is not possible you must maintain a safe working distance from any exposed conductors.
Keep your work areas clear. Do not unnecessarily open covers, shields or guards. Replace them immediately when you have completed your work task. This rule applies even if you have planned further work at a later stage.
Where necessary place safety warning signs and barriers to protect both yourself and others.
Other people who may be affected by your work
Ensure that your work is not causing any safety hazard to other people in the building. Place warning and information signs as required. Agree with the building owner or his representatives about the appropriate safety measures. Keep the machine room doors locked unless you are working in there.
When working in the lift well and it is necessary to keep the landing door open, protect the working areas on the landings so that other building users cannot come into contact with elevator equipment. The entrance protection should be constructed according to the local regulations.
The elevator and its associated equipment
Take time to familiarize yourself with the elevator if it is new to you. This is particularly important when working with other manufacturers equipment where the level of training and information available may vary and circuit diagrams are in an unfamiliar style . Even if you have worked on the same elevator before check for possible changes, (where applicable refer to the elevator log book for past service history). Ensure that you know the location of all isolators and fuses.
Ensure you have adequate information to do the work and fully understand all the possible effects of your actions.
Read the manuals, circuit and wiring diagrams and other available relevant material. Ensure that the material you are reading is up to date - IF IN DOUBT - ASK. Talk to your supervisor if you have any doubts about the working method or safety related issues.
Environment
Check that there is no potential hazard for yourself or others in the immediate vicinity of the elevator, (other equipment, water, oil leaks etc., ...).
Do not cause environmental hazards. Use suitable containers for the removal of old rope oil. Follow your local regulations when hazardous waste needs disposal.
Areas of Special Risk
Assess requirements for safety signage, high voltage warnings and procedures. Ensure there is sufficient lighting for you to do your work safely.
If working in a multiple well installation ensure you are not at risk from moving parts of an adjacent elevator. If there is no well protection between adjacent elevators, if possible, arrange for the adjacent elevators to be switched off and keep all the cars at the same working level.
If it is not possible to switch off adjacent elevators ensure you maintain a safe working distance from all moving parts.
Be aware of the risks from overcrowding if more than one person is working in a restricted space. Be aware of the risks from unexpected movement of the elevator or associated components.
Watch out for other hazards such as oil, tripping etc.
Check all the supplies to the elevator including lighting supplies and any other optional devices. Check also for possible emergency backup supplies, common supplies to all elevators in the case of multiple installations and other “kick back” energy sources.
Protect Yourself
Before commencing work in the lift well area ensure that you can exit the well quickly and safely in all circumstances.
Do not deviate from the prescribed working method.
Use personal protective equipment as required. Wherever possible, avoid working on live equipment when you are on your own.
Never attempt to make repairs when equipment is live.
When it is necessary to work with live equipment take extreme care to avoid any possibility of hand to hand, or hand to foot/leg electric shock. Keep one hand away from the electrical conductors and any possible earthing connections. Use clip on leads for the test equipment particularly on the negative terminal.
When working on an elevator installation there are many components which are likely to be at earth potential, these can include control panels, connection boxes and trunking, landing doors, guide rails and ropes.
Do not wear jewelry, I.D. badges with metal chains or other loose items of conducting material which may put you at risk.
Evaluate the situation
ALWAYS ASSUME THAT EQUIPMENT IS STILL LIVE UNTIL IT HAS BEEN LOCKED, TAGGED AND
TESTED FOR ZERO ENERGY STATE - Locking and tagging must be used wherever possible
Always test, using approved equipment that equipment is safe, i.e., DE-ENERGISED. Do not rely on led’s or other indicator lights and always allow sufficient time for all stored energy to discharge.
Check the measuring tools to ensure they are operative.
Ensure that switching off the power will not affect other people (e.g., people in the elevator car).
STEPS TO ENSURE ELECTRICAL SAFETY
1. Disconnect power supply completely
- Safe procedures for de-energizing the equipment shall be determined before circuits are de- energized.
- Ensure ALL electrical energy sources are identified and disconnected including elevator main switch, lighting switches, auxiliary supplies, emergency batteries, and emergency generators.
- All stored energy must be released. Do not attempt to discharge capacitors, this is highly dangerous and will damage the equipment. Allow capacitors to discharge normally and then test to ensure that they are safely de-energized. Secure any machinery that may be capable of producing electrical energy from moving.
- WARNING! When rotated manually, for example when moving the car/counterweight by releasing the brake, machines will act as generators and may recharge the intermediate circuit to some extent even though the power is turned off.
- Depending on the work task it may be necessary for other non-electrical stored energy to be made safe, (counterweight/car may need supporting and in the case of hydraulic systems a pit prop may be required.) Ensure there is no other possibility of moving equipment that may cause, trapping, falling or crushing hazards.
CAUTION:- The drawings shown in this document are typical examples based on to the most common elevator component layouts. The components and their positions may vary between deliveries. Special attention must be paid to ensure that all circuits are isolated.
2. Secure against re-connection
- A lock and tag must be placed on each switch. Always lock the switch. If this is not possible agree an alternative safe method with your supervisor.
- The tag must state clearly:
- The equipment MUST NOT be turned on.
- The name of the person responsible for removing the tag.
- If it is not possible to fit a lock one additional safety element to the tag must be provided, (e.g., removal of fuses and storage in a secure place).
3. Verify that the installation is de-energized
Test and inspect that the circuit is safely de-energized using suitable approved test equipment. The test must verify that:
- There are no energized circuits.
- There are no related risks from capacitance, induced voltages or other feedback.
WARNING:- Inverter drives (UPS) usually remain energized for about 5 minutes after the power has been disconnected. DO NOT work on the drive, hoisting motor or braking resistors until you have verified that this energy has been discharged.
Where voltages above 600V DC or 400V AC are tested the test equipment must be checked before and after the test.
4. Check the requirements for earthing in special circumstances
- Emergency Back Up Supplies (in the event of mains power failure)
- Some buildings such as hospitals and large computing facilities are equipped with emergency power supplies, usually these are generators but sometimes a completely independent power source is utilized.
- It is essential that you, together with your supervisor, liaise with the building owner or his appointed representative to verify that the emergency backup supply is also safely disconnected from the elevator equipment and that this disconnection has not impaired the function of other essential facilities in the building.
- Bonding of Conductors
- This is employed in very rare cases where the isolation of electrical equipment is made at a remote location and it is considered necessary for safety reasons.
- This technique is not normally used with low voltage (below 1000v ac) supplies.
- The operation may only be carried out by qualified personnel in co-operation with the person responsible for the building electrification who must ensure that the technique can be safely employed in this situation.
- When this technique is employed, all conductors supplying the elevator equipment should be bonded together and to the MAIN EARTH of the building. Earth bonding may be achieved by connecting conductors of suitable size to carry the potential short circuit currents to the electrical installation earthing system.
5 Provide protection against adjacent live parts
If there are parts of an electrical installation in the vicinity of the work location, that cannot be de- energized, then special additional precautions are necessary and shall be applied before work starts.
- Provide protection by screen, barrier, enclosure or insulating covering.
- If the measures above cannot be carried out, protection shall be provided by maintaining a safe distance to bare live parts and when necessary, providing appropriate supervision.
WARNING: When working in the vicinity of moving parts (For example, a neighbour elevator left in use), the additional protections may be needed.
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