Work on Electrical Installations and in premises presenting a fire or explosion hazard

Definitions and concepts:

All work on an electrical installation or in its vicinity that entails an electrical hazard is to be carried out with the power supply off, except:

Basic operations: connection and disconnection in LV installations, with suitable electrical material and without any risk to the public.
Work on installations under safety voltage, when there exists no risk of confusion (complex installations) or burns (the installations conveys high currents).
Manoeuvres, measurements, tests and checks that so require it: opening/closing of switches or circuit-breakers, measurement of current, insulation tests, checking phase concordance.
Work on or in the vicinity of installations whose conditions of exploitation/continuity so require it. For instance: requirements to comply with Quality and Continuity Regulations (Spanish Royal Decree 1955/2000); the cut-off of supply supposes risks for the health and safety of the population or of a group of persons within said population.

TABLE OF LIMIT DISTANCES FOR WORK AREAS
Vr	DDAN-1	DDAN-2	DPROX-1	DPROX-2
≤ 1	50	50	70	300
3	62	52	112	300
6	62	53	112	300
10	65	55	115	300
15	66	57	116	300
20	72	60	122	300
30	82	66	132	300
45	98	73	148	300
66	120	85	170	300
110	160	100	210	500
132	180	110	330	500
220	260	160	410	500
380	390	250	540	700
Vr = rated voltage of the installation in (kV). DDAN-1= distance to the outer limit of the danger zone when there is a risk of overvoltage caused by lightning (cm). DDAN-2= distance to the outer limit of the danger zone when there is no risk of overvoltage caused by lightning (cm). DPROX-1= distance to the outer limit of the proximity zone when it is possible to precisely demarcate the work area and to establish controls that impede workers from going beyond this limit during the carrying out of such work (cm). DPROX-2= distance to the outer limit of the proximity zone when it is not possible to precisely demarcate the work area or to establish controls that impede anyone from going beyond this limit during the carrying out of such work (cm).
(Note): For intermediate voltage values, the distances corresponding to the voltage value that figures in the table and which is immediately superior to the actual voltage value are to be considered.

SUMMARY CHART FOR MINIMUM STAFF TRAINING/QUALIFICATIONS
	Non-voltage work		Live work		Manoeuvres, measurements, tests and checks		Proximity work
	Supression and reconnection of voltage	Non-voltage work	Carrying out of	Replacing fuses	Measurements, tests and checks	Local manoeuvres	Preparation of	Carrying out of
Low Voltage	A	T	C	A	A	A	A	T
High Voltage	C	T	C+AE (supervised by a Foreman)	C	C o C assisted by A	A	C	A o T supervised by A
T= Any worker A= Authorised worker C= Qualified worker C+AE= Qualified and authorised in writing				1. HV work with electrical hazards cannot be carried out by workers from a Temporary Work Company (Spanish Royal Decree 216/1999). 2. The carrying out of the different activities considered is to be done in accordance with the stipulations of the present Spanish Royal Decree.

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