MICC CURRENT RATINGS - R&M Electrical Group

1 TABLE 4G1A Mineral insulated cables thermoplastic covered or bare and exposed to touch (copper conductors & sheath)30 C Ambient Air Temperature,70 C Conductor Operating Temperature, CURRENT Carrying Capacity (amperes)single phase or phase or :For single core cables, the sheaths of the circuit are assumed to be connected together at both endsFor bare cables exposed to touch, the tabulated values should be multiplied by tables for guidance purposes only. R&M accepts no responsibility for the information contained hereinTABLE 4G2A Mineral insulated cables bare and neither exposed to touch nor in contact with conbustible materials (copper conductors & sheath)30 C Ambient Air Temperature, CURRENT Carrying Capacity (amperes)

2 105 C Conductor Operating Temperature,single phase or phase or single core cables, the sheaths of the circuit are assumed tobe connected together at both endsNo rating factor for grouping need be appliedWhere a conductor operates at a temp0erature exceeding 70 C it shall be ascertained that the equipment connected to the conductor is suitable for the conductor operating tables for guidance purposes only. R&M accepts no responsibility for the information contained hereinVOLTAGE DROPTABLE 4G1B Mineral insulated cables thermoplastic covered or bare and exposed to touch (copper conductors & sheath)70 C Sheath Operating TemperatureVoltage Drop (per ampere per meter) single phase or crosssectional area mm 16rxzrxz25 - - 50 - - 70 - - 95 - - - - - - - - - - 3 single core cables in trefoil, or 1 three core or four core cable2 single cordcablestouching or 12core cableConductor cross- sectional area mm Reference Method C (Clipped Direct)

3 Reference Method E, F & G(in free air or on a perforated cable tray etc, horizontal or vertical)three phase phase single core cables flat & spaced by one cable diameter3 single core cables flat and touching, horizontal or vertical3 single core cables in trefoil, or 1 three core or four core cable2 single cordcablestouching or 12 core cable3 single core cables flat and touching, horizontal or verticalTwo- core cable, touching 1 two- core cablemV/A/mmV/A/m4242 Conductor cross- sectional area mm Reference Method C (Clipped Direct)Reference Method E, F & Gthree phase phase single corecables3 single core cables in trefoil, or 1 three 3 single core cables flat and touching, horizontal 2 single corecables3 single core cables in trefoil, or 1 three core or four core 3 single core cables flat and touching3 single core cables flat & CURRENT RATINGSTABLE 4G1A Mineral insulated cables thermoplastic covered or bare and exposed to touch (copper conductors & sheath)30 C Ambient Air Temperature,70 C Conductor Operating Temperature, CURRENT Carrying Capacity (amperes)single phase or phase or.

4 For single core cables, the sheaths of the circuit are assumed to be connected together at both endsFor bare cables exposed to touch, the tabulated values should be multiplied by tables for guidance purposes only. R&M accepts no responsibility for the information contained hereinTABLE 4G2A Mineral insulated cables bare and neither exposed to touch nor in contact with conbustible materials (copper conductors & sheath)30 C Ambient Air Temperature, CURRENT Carrying Capacity (amperes)105 C Conductor Operating Temperature,single phase or phase or single core cables, the sheaths of the circuit are assumed tobe connected together at both endsNo rating factor for grouping need be appliedWhere a conductor operates at a temp0erature exceeding 70 C it shall be ascertained that the equipment connected to the conductor is suitable for the conductor operating tables for guidance purposes only.

5 R&M accepts no responsibility for the information contained hereinVOLTAGE DROPTABLE 4G1B Mineral insulated cables thermoplastic covered or bare and exposed to touch (copper conductors & sheath)70 C Sheath Operating TemperatureVoltage Drop (per ampere per meter) single phase or crosssectional area mm 16rxzrxz25 - - 50 - - 70 - - 95 - - - - - - - - - - 3 single core cables in trefoil, or 1 three core or four core cable2 single cordcablestouching or 12core cableConductor cross- sectional area mm Reference Method C (Clipped Direct)Reference Method E, F & G(in free air or on a perforated cable tray etc, horizontal or vertical)three phase phase single core cables flat & spaced by one cable diameter3 single core cables flat and touching, horizontal or vertical3 single core cables in trefoil, or 1 three core or four core cable2 single cordcablestouching or 12 core cable3 single core cables flat and touching, horizontal or verticalTwo- core cable, touching 1 two- core cablemV/A/mmV/A/m4242 Conductor cross- sectional area mm Reference Method C (Clipped Direct)

6 Reference Method E, F & Gthree phase phase single corecables3 single core cables in trefoil, or 1 three 3 single core cables flat and touching, horizontal 2 single corecables3 single core cables in trefoil, or 1 three core or four core 3 single core cables flat and touching3 single core cables flat & CURRENT RATINGSC onductor crosssectional area mm 3 single core cables flat and touchingmV/ - - - - - - - - - - - - - - - - larger thanone cable dia will reuslt in a larger volt dropVOLTAGE DROPTABLE 4G2B Mineral insulated cables bare and neither exposed to touch nor in contact with conbustible materials (copper conductors & sheath)Voltage Drop (per ampere per meter)

7 Single phase or crosssectional area mm - - - - - - - - - - - - - - - - Conductor crosssectional area mm 3 single core cables flat and touchingmV/ - - - - - - - - - - - - - - - - larger thanone cable dia will reuslt in a larger volt drop3 single core cables flat and spaced by one cable three core or four core cable3 single core cables in trefoil formationmV/A/mmV/ core cable, touching 1 two- core cablemV/A/mmV/ three core or four core cable3 single core cables in trefoil formation3 single core cables flat and spaced by one cable