List of external influences

Figure E46 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	Specially designed equipment or appropriate arrangements
AA1	- 60 °C	+ 5 °C
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 °C	15	100	0.04	36

AC	Altitude
AC1	y 2000 m		Normal
AC2	> 2000 m		May necessitate precaution (derating factors)
AD	Presence of water
AD1	Negligible	Outdoor or non-weather protected locations	IPX0
AD2	Free falling drops		IPX1 or IPX2
AD3	Sprays		IPX3
AD4	Splashes		IPX4
AD5	Jets	Locations where hose water is used regularly	IPX5
AD6	Waves	Seashore locations (piers, beaches, quays…)	IPX6
AD7	Immersion	Water 150 mm above the highest point and equipment not more than 1m below the surface	IPX7
AD8	Submersion	Equipment is permanently and totally covered	IPX8

AE	Presence of foreign solid bodies
		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 stress impact
AG1	Low severity		Normal
AG2	Medium severity		Standard where applicable or reinforced material
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
AJ	Other mechanical stresses
AK	Presence of flora and/or mould growth
AH1	No hazard		Normal
AH2	Hazard
AL	Presence of fauna
AH1	No hazard		Normal
AH2	Hazard
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	Refer to applicable IEC standards
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
AQ1	Low	Normal
AQ2	Medium
AQ3	High
AS	Wind
AQ1	Low	Normal
AQ2	Medium
AQ3	High
B - Utilization
BA	Capability of persons
BA1	Ordinary	Normal
BA2	Children
BA3	Handicapped
BA4	Instructed
BA5	Skilled
BB	Electrical resistance of human body
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. E46: List of external influences (taken from Appendix A of IEC 60364-5-51)