Contact EDP Distribuição in order to know the line's characteristics and the distances to allow and, if the situation merits it, whether the line can be placed out of service for a period of time during some particular stage of the work.
The use of moving machinery near electric lines must be considered a dangerous work which requires knowledge and training on the part of the operator and all the workers involved in the works.
An experienced person on the ground should be designated with the task to pay close attention to the movement of the machines and the load to prevent them coming dangerously close to the electric voltage conductors.

Avoid the storing of materials near or below high-voltage electric lines.
If possible, establish paths so that the machines avoid crossing electric lines.
Place obstacles and warning signs alongside line conductors at appropriate distances.
Place height-limiting markers on each side of a place which involves crossing an electric line.
Install boards with warnings at the entrances of workplaces and places where there is frequent moving machinery below or near the electric line.
 

Works with Cranes or Moving Machinery Close to High-Voltage Electric Lines

Respect the safety distances recommended by EDP, and maintain these between the conductors and any part of the crane or load.

For power lines up to 60 kV : 3 metres; 
For power lines greater than 60 kV : 5 metres.

Whenever possible place limit switch breakers on the moveable items whose movement could lead the machine or the load to enter an off-limits area as delimited by the distances previously mentioned.

Machines in movement with a low jib or unloaded, and under the supervision of a manager, can be allowed through a passage:
-1.5 metres for voltage lines lower than 60 kV (Medium Voltage) 
-3 metres for voltage lines between 60 kV and 220 kV; 
-5 metres for voltage lines greater than 220 kV.
In the event of frequent crossings the preventative markers should be set to their maximum height.

Any electric conducting line must be considered as active, unless there is a written indication from a representative of EDP confirming that the conductors are not carrying power and that they have been grounded.

Independently of this indication, whenever the line is without electric power, in order to be considered as such, the conductors should be grounded in the workplace.

Works Below Live Electric Lines, Namely on Flat Roofs

Workers must be instructed about the risks of electricity and safety distances.
For workers who are not electricians, the minimum safety distances to maintain between line conductors and the workers, or any tool or material they handle, are:
-3 metres for voltage lines up to 60 kV
-5 metres for voltage lines greater than 60 kV.
 

Obtain information about their presence from EDP Distribuição and, if this is the case, the special measures to be adopted.

Identification and field marking of the path of the cable must be carried out in a clearly visible manner by the company which is going to carry out the works, in conjunction with EDP.If the words are to be carried out less than 1.50 m from insulated electric tubing, the works must be executed with the presence of a qualified person from the company which is going to carry out the works.Approximation to the tubing should be carried out with hand-held tools (spade or shovel), taking care not to damage the tubing. It is not permitted to use a pickaxe near the tubing. 

If mechanical tools are to be used:

> if the tubing is visible, an observer can ensure that the machine does not come any closer than 0.30 m to the tubing;

> if the tubing is not visible, the minimum estimated distance will be 0.50 m and observation must be kept reinforced.

If there is any doubt regarding the distances or the signposting of the presence of the tubing, approximation should be carried out manually, taking any and all necessary care to not damage the insulation of the cable.