List of external influences

Figure E61 below is from IEC 60364-5-51, which should be referred to if further details are required.

Code	External influences						Characteristics required for equipment
A - Environment
AA	Ambient temperature (°C)
	Low	High
AA1	- 60 °C	+ 5 °C					Specially designed equipment or appropriate arrangements
AA2	- 40 °C	+ 5 °C
AA3	- 25 °C	+ 5 °C
AA4	- 5° C	+ 40 °C					Normal (special precautions in certain cases)
AA5	+ 5 °C	+ 40 °C					Normal
AA6	+ 5 °C	+ 60 °C					Specially designed equipment or appropriate arrangements
AA7	- 25 °C	+ 55 °C
AA8	- 50° C	+ 40 °C
AB	Atmospheric humidity
	Air temperature (°C)		Relative humidity (%)		Absolute humidity (g/m3)
	Low	High	Low	High	Low	High
AB1	- 60 °C	+ 5 °C	3	100	0.003	7	Appropriate arrangements shall be made
AB2	- 40 °C	+ 5 °C	10	100	0.1	7
AB3	- 25 °C	+ 5 °C	10	100	0.5	7
AB4	- 5° C	+ 40 °C	5	95	1	29	Normal
AB5	+ 5 °C	+ 40 °C	5	85	1	25	Normal
AB6	+ 5 °C	+ 60 °C	10	100	1	35	Appropriate arrangements shall be made
AB7	- 25 °C	+ 55 °C	10	100	0.5	29
AB8	- 50 °C	+ 40	15	100	0.04	36
AC	Altitude
AC1	≤ 2000 m						Normal
AC2	> 2000 m						May necessitate precaution (derating factors)
AD	Presence of water
AD1	Negligible		Probability of presence of water is negligible				IPX0
AD2	Free falling drops		Probability of presence of water is negligible				IPX1 or IPX2
AD3	Sprays		Possibility of water falling as a spray at an angle up to 60° from the vertical				IPX3
AD4	Splashes		Possibility of splashes from any direction				IPX4
AD5	Jets		Possibility of jets of water from any direction				IPX5
AD6	Waves		Possibility of water waves (seashore locations)				IPX6
AD7	Immersion		Possibility of intermittent partial or total covering by water				IPX7
AD8	Submersion		Equipment is permanently and totally covered				IPX8
AE	Presence of foreign solid bodies or dust
			Smallest dimension		Example
AE1	Negligible						IP0X
AE2	Small objects		2.5 mm		Tools		IP3X
AE3	Very small objects		1 mm		Wire		IP4X
AE4	Light dust						IP5X if dust penetration is not harmful to functioning IP6X if dust should not penetrate
AE5	Moderate dust
AE6	Heavy dust						IP6X
AF	Presence of corrosive or polluting substances
AF1	Negligible						Normal
AF2	Atmospheric						According to the nature of the substance
AF3	Intermittent, accidental						Protection against corrosion
AF4	Continuous						Equipment specially designed
AG	Mechanical shock
AG1	Low severity						Normal, e.g. household and similar equipment
AG2	Medium severity						Standard industrial equipment, where applicable, or reinforced protection
AG3	High severity						Reinforced protection
AH	Vibrations
AH1	Low severity		Household or similar				Normal
AH2	Medium severity		Usual industrial conditions				Specially designed equipment or special arrangements
AH3	High severity		Severe industrial conditions
AK	Presence of flora and/or moulds growth
AK1	No hazard						Normal
AK2	Hazard						Special protection
AL	Presence of fauna
AL1	No hazard						Normal
AL2	Hazard						Special protection
AM	Electromagnetic, electrostatic or ionising influences / Low frequency electromagnetic phenomena / Harmonics
AM1	Harmonics, interharmonics						Refer to applicable IEC standards
AM2	Signalling voltage
AM3	Voltage amplitude variations
AM4	Voltage unbalance
AM5	Power frequency variations
AM6	Induced low-frequency voltages
AM7	Direct current in a.c. networks
AM8	Radiated magnetic fields
AM9	Electric field
AM21	Induced oscillatory voltages or currents
AM22	Conducted unidirectional transients of the nanosecond time scale
AM23	Conducted unidirectional transients of the microsecond to the millisecond time scale
AM24	Conducted oscillatory transients
AM25	Radiated high frequency phenomena
AM31	Electrostatic discharges
AM41	Ionisation
AN	Solar radiation
AN1	Low						Normal
AN2	Medium
AN3	High
AP	Seismic effect
AP1	Negligible						Normal
AP2	Low severity
AP3	Medium severity
AP4	High severity
AQ	Lightning
AQ1	Negligible						Normal
AQ2	Indirect exposure
AQ3	Direct exposure
AR	Movement of air
AR1	Low						Normal
AR2	Medium
AR3	High
AS	Wind
AS1	Low						Normal
AS2	Medium
AS3	High
B - Utilization
BA	Capability of persons
BA1	Ordinary						Normal
BA2	Children
BA3	Handicapped
BA4	Instructed
BA5	Skilled
BB	Electrical resistance of human body (under consideration)
BC	Contact of persons with earth potential
BC1	None						Class of equipment according to IEC61140
BC2	Low
BC3	Frequent
BC4	Continuous
BD	Condition of evacuation in case of emergency
BD1	Low density / easy exit						Normal
BD2	Low density / difficult exit
BD3	High density / easy exit
BD4	High density / difficult exit
BE	Nature of processed or stored materials
BE1	No significant risks						Normal
BE2	Fire risks
BE3	Explosion risks
BE4	Contamination risks
C - Construction of building
CA	Construction materials
CA1	Non combustible						Normal
CA2	Combustible
CB	Building design
CB1	Negligible risks						Normal
CB2	Propagation of fire
CB3	Movement
CB4	Flexible or unstable

Fig. E61 – List of external influences (taken from Appendix A of IEC 60364-5-51)