Bühne

General technical information on circular connectors

HUMMEL-Connectors may not be connected or disconnected under voltage. In order to guarantee the IP protection class and the necessary contact overlapping, the cable and coupling connectors must be inserted and locked as far as it will go.

Clearance / creepage distance

The air gap is the shortest distance in air between two conductive parts.

The clearances in HUMMEL products are dimensioned for altitudes up to and including 2000 m above sea level (NN). For air distances over 2000 m, altitude correction factors apply, please contact our technical specialist.

The creepage distance is the shortest distance along the surface of an insulating material between two conductive parts.

Connectors / plugs

Plug devices are plug-in connectors which, when used as intended, live or under load, may be plugged in or disconnected. Sockets are also known as CBC (connector with breaking capacity). A classic example from the household is the SCHUKO plug.

Connectors that may not be plugged in or disconnected under load or live when used as intended are also called COC (connector without breaking capacity).

HUMMEL connectors are usually classified as COC, so they must not be connected or disconnected when live!

Derating curve / warming

The derating curve (current-carrying capacity curve) describes the maximum permissible power loss of an electrical or electronic component as a function of its ambient temperature below its upper limit temperature (see above). The configuration and wiring of the component is important for this (number and cross-section of the energized conductors in connectors).

  • The heating is measured as the temperature difference (∆T) to the environment at nominal current.
  • The base curve describes the real, measured temperature at the warmest point of the component at the corresponding ambient temperature.
  • The derating curve is calculated (in accordance with EN 60512-5-2) by reducing the current value by 20% of the base curve.
  • The rated current limits the current to a maximum value.

Example: In the curve, the component should only be operated up to 40 A at an ambient temperature of 100°C without exceeding the upper limit temperature.

Degree of pollution

The degree of pollution is a numerical value that indicates the expected pollution of the microenvironment and is a parameter when dimensioning the air and creepage distances in electrical equipment. It describes the possible contamination of an open, unmated connector in a certain environment. The EN 60664-1 standard distinguishes between four categories:

  • Pollution degree 1: No pollution or only dry, non-conductive pollution occurs. The pollution has no influence.
  • Pollution degree 2: Only non-conductive pollution occurs. Occasionally, however, temporary conductivity due to condensation must be expected. (Typical for households, business premises, laboratories or test areas.)
  • Pollution degree 3: Conductive pollution occurs or dry, non-conductive pollution that becomes conductive because condensation is to be expected. (typical for industrial companies or workshops.)
  • Pollution degree 4: There is permanent conductivity, caused by conductive dust, rain or moisture.

If connectors are used with a higher degree of pollution, the voltage values must be reduced. Please contact our technical specialists.

Flammability / flame class

UL94 is a standard used by the American test laboratory Underwriters Laboratories, in which the burning properties and fire safety of plastics are examined. The UL 94 HB (Horizontal Burning) test tests the burning of a horizontal piece of plastic and the more demanding test UL 94 V (Vertical Burning) tests the burning of a vertical piece. The exact explanations about the systems used, the conditions and the test system can be found in the written UL 95 standard.

Example: UL identification for flammability UL 94 V (test of vertical combustion)

Flammability classes UL 94
  V-0 V-1 V-2
Afterburning time after flame treatment (s) ≤ 10 ≤ 30 ≤ 30
Sum of all afterburning times (s)
(10 flames)
≤ 50 ≤ 250 ≤ 250
Afterburning and afterglow of the samples after the second flame (s) ≤ 30 ≤ 60 ≤ 60
Burning dripping
(ignition of the absorbent cotton)
No No Yes
Complete burning of the samples No No No
Functional earth (FE)

Functional earth (FE) is an electrical conductor, to ensure the functions and thus the regular operation of systems and devices.

Functional earth conductor: Grounding conductor for the purpose of functional grounding.

Functional ground: Earthing of a point or several points in a network, a system or an operating device for purposes other than electrical safety.

IP protection class (contact protection, dust, water)

With regard to their suitability for various environmental conditions, electrical equipment is designed in accordance with EN 60529 with suitable degrees of protection expressed by IP codes. The abbreviation IP stands for Ingress Protection (protection against ingress). The letters IP are followed by 2 digits describing protection against foreign bodies/contact (st digit) and protection against water (2nd digit).

To ensure the IP protection class and the necessary contact overlap, the cable connector and the coupling connector must be plugged in and locked up to the stop.

Limit temperature

Upper and lower temperatures that do not damage the materials are referred to as limit temperatures. In between lies the operating temperature range (e.g. -40 ... +125°C)

The lower limit temperature is the lowest permissible temperature at which a connector or plug device may still be operated

The upper limit temperature is the highest permissible temperature at which a plug connector or plug device may still be operated. It is equal to the sum of self-heating (contact heating and heating of the cable) and the maximum ambient temperature.

Mating Cycles

An insertion and removal process of connectors is referred to as a mating cycle. The number of mating cycles is an important parameter for plugs and connectors. It defines the service life of a connector, which it can complete without any loss of transmission quality. The quality of the contact surface in particular has an influence on the number of mating cycles. The use of high-quality and durable contact coatings reduce surface abrasion during the mating process.

Overlapping contacts

In general, contact overlap or mating security in connectors refers to the possible overlap area of pin and socket. The larger this area, the more reliable the connection due to the higher possible tolerance compensation.

At HUMMEL, in order to guarantee the IP protection class and the necessary contact coverage, cable and coupling connectors must be plugged in and locked as far as they will go.

Overvoltage category

The overvoltage category is a (Roman) numerical value that defines a condition with regard to transient overvoltages for equipment that is fed directly from the low-voltage network:

  • CAT IV: Equipment for use at the connection point of the installation (electricity meters, primary overcurrent protection devices, etc.)
  • CAT III: Equipment in fixed installations and for those cases in which special requirements are placed on the reliability and availability of the equipment. (Switches in permanent installations and equipment for industrial use with permanent connection to the permanent installation)
  • CAT II: Energy-consuming equipment that is fed by the fixed installation (household appliances, portable tools and other household appliances and similar devices). [However, if such devices are subject to special requirements in terms of reliability and availability, CAT III must be used.]
  • CAT I: Circuits that are connected to the mains but suitable measures have been taken to limit transient overvoltages.
  • Without CAT information: circuits that have no direct connection to the network. Example: In battery operation or behind a transformer that offers double / reinforced insulation (e.g. devices of protection class 3 - operation with protective extra-low voltage, car electrics, controls, PLC, motor controls)
Protective conductor (PE)

Protective conductor (PE) is an electr. conductor for the purpose of safety, for example to protect against electric shock. It is also known as the earth conductor, or “earth” for short. Task in electr. Systems is the protection of living beings in the event of a failure.

PE conductor: Protective conductor for the purpose of protective earthing

Protective earthing: earthing of one or more points in the network, in a system or in equipment for the purpose of electrical safety.

Rated current

The rated current is the current value, preferably at an ambient temperature of 40°C, which the connector can carry continuously (without interruption) and which flows simultaneously through all contacts connected to the largest fixed conductor without exceeding the upper limit temperature.

When considering the current carrying capacity of the connector, the current carrying capacity of the lines and cables used must be taken into account. This is primarily dependent on the permissible limit temperatures (see below), but also on the cross-section of the conductors and their bundling and installation situation. To this end, the manufacturer's instructions or standards such as: DIN VDE 0298-4 or IEC 60364-5-52 must be observed. Here are some extracts from DIN VDE 0298-4:

Tables according to installation type:

Source: DIN VDE 0298-4

Laying type     

A1 A2 B1 B2 C
Installation in thermally insulated walls Laying in electrical installation pipes Laying on a wall
Number of loaded cores 2 3 2 3 2 3 2 3 2 3
Nominal cross-section in mm2 Load capacity in A
  1,5 15,5   13,5  15,5  13 17,5  15,5  16,5  15 19,5  17,5
  2,5 19,5 18 18,5 17,5  24 21 23 20 27 24
  4 26 24 25 23 32 28 30 27 36 32
  4 - - - - - - - - - 33,02 
  6 34 31 32 29 41 36 38 34 46 41
  10 46 42 43 39 57 50 52 46 63 57
  10 - - - - - - - 47,17  - 59,43
  16 61 56 57 52 76 68 69 62 85 76
  25 80 73 75 68 101 89 90 80 112 96
  35 99 89 92 83 125 110 111 99 138 119
  50 119 108 110 99 151 134 133 118 168 144
  70 151 136 139 125 192 171 168 149 213 184
  95 182 164 167 150 232 207 201 179 258 223
  120 210 188 192 172 269 239 232 206 299 259
  150 240 216 219 196 300 262 258 225 344 299
  185 273 245 248 223 341 296 294 255 392 341

 

Source: DIN VDE 0298-4

Laying type D E F G
Laying in earth Laying in the air
Number of loaded cores 2 3 2 3 2 3 2
Nominal cross-section in mm2 Load capacity in A
1,5 22 18 22 18,5 - - - - -
2,5 29 24 30 25 - - - - -
4 37 30 40 34 - - - - -
6 46 38 51 43 - - - - -
10 60 50 70 60 - - - - -
16 78 64 94 80 - - - - -
25 99 82 119 101 131 114 110 146 130
35 119 98 148 126 162 143 137 181 162
50 140 116 180 153 196 174 167 219 197
70 173 143 232 196 251 225 216 281 254
95 204 169 282 238 304 275 264 341 311
120 231 192 328 276 352 321 308 396 362
150 261 217 379 319 406 372 356 456 419
185 292 243 434 364 463 427 409 521 480
240 336 280 514 430 546 507 485 615 569
300 379 316 593 497 629 587 561 709 659

 

Conversion factors for different ambient temperatures:

Source: DIN VDE 0298-4
Permissible operating temperature 40°C 60°C 70°C 80°C 85°C 90°C
Ambient temperature in °C Conversion factors
10 1,73 1,29 1,22 1,18 1,17 1,15
15 1,58 1,22 1,17 1,14 1,13 1,12
20 1,41 1,15 1,12 1,10 1,09 1,08
25 1,22 1,08 1,06 1,05 1,04 1,04
30 1,00 1,00 1,00 1,00 1,00 1,00
35 0,71 0,91 0,94 0,95 0,95 0,96
40 - 0,82 0,87 0,89 0,90 0,91
45 - 0,71 0,79 0,84 0,85 0,87
50 - 0,58 0,71 0,77 - 0,82
55 - 0,41 0,61 0,71 - 0,76
60 - - 0,50 0,63 - 0,71
65 - - 0,35 0,55 - 0,65
70 - - - 0,45 - 0,58
75 - - - 0,32 - 0,50
80 - - - - - 0,41
85 - - - - - 0,29
Rated surge voltage

The rated impulse voltage is the value of a withstand impulse voltage that is specified by the manufacturer for a piece of equipment or for a part of it and which indicates the specified withstand capability of its associated insulation against transient overvoltages.

The level of the value is a measure of the minimum required air gap in the equipment.

Source: Table F1 of EN 60664-1
Voltage conductor to neutral conductor, derived from the nominal AC or nominal DC voltage up to and including Rated impulse voltage
Overvoltage category
I II III IV
V V V V V
50 330 500 800 1500
100 500 800 1500 2500
150 800 1500 2500 4000
300 1500 2500 4000 6000
600 2500 4000 6000 8000
1000 4000 6000 8000 12000
Rated voltage

The rated voltage is the specified value of the voltage to which the operating and performance characteristics are related. A connector can have more than one value of the rated voltage for the different voltage systems.

HUMMEL connectors can be used for DC (V=) and AC voltage (V~). For these cases, the rated voltage of the effective value of the maximum rated voltage line to neutral (UL-N). In 3-phase three-phase systems (V3~), the rated voltage is specified as phase voltage / conductor to conductor (UL-L).

In earthed networks (TN, TT, TN-C, TN-CS, ...) the voltage conductor to earth (UL-PE) is √3 less than the phase voltage (UL-L). In ungrounded networks, the conductor to earth voltage (UL-PE) is calculated to be the same as the conductor to conductor voltage (UL-L), i.e. not reduced by √3 because the star point (N) is not connected to earth (PE) is! This is important for dimensioning the clearances.

Test voltage

The test voltage is the voltage that a connector has to withstand under certain specifications without a voltage surge or voltage breakdown occurring over or through the insulation and corresponds at least to the withstand voltage in EN 61984.

The value of the test voltage is higher than the rated voltage and is used to verify the insulation capacity of the connector.

Security notice

For operating voltages greater than 50 volts, the plug-in connectors listed in this catalog must have conductive housing parts in accordance with the safety regulations of DIN VDE 0100-410; IEC 60364-4-41 can be used. These safety regulations stipulate that the corresponding plug connectors must not be plugged in or disconnected while live. Otherwise no protection against electric shock is guaranteed.