# Flex Fusing

The Flex System input power distribution is designed for daisy chaining a current of 32 A maximum. The system is approved with the Atlas Copco 32 A power cable only. This sets the maximum allowed fusing for one chain to 32 A. When using external fuse it is recommended to use a slow blow, Class CC.

In both the fusing tables it is assumed that all channels/tools are set up to do a synchronized simultaneous tightening. If this is not the case, like for some kind of stitching operation, then go with a fuse value according to the actual number of simultaneous tightenings.

The fusing tables presents the recommended values for one daisy chained mains power supply (one fuse) with normal performance.

FlexSystem channels | Recommended external fuse QST42 | Recommended external fuse QST50 | Recommended external fuse QST62 | Recommended external fuse QST80/90
--- | --- | --- | --- | ---
2 | 16 A | 16 A | 16 A | 20 A
5 | 20 A | 20 A | 20 A | 30 A
8 | 20 A | 20 A | 25 A | 32 A
11 | 20 A | 25 A | 30 A | 35 A
14 | 25 A | 30 A* | 32 A [Max] | 45 A

* Simultaneous tightening with 14 tools of QST50 type on a soft joint with 75 Nm final tightening torque.

Tool count for a given fuse value (one power chain) with approximately 75% of maximum performance

Tool type | No of tools – 32A | No of tools – 25A | No of tools – 20A
--- | --- | --- | ---
QST42 | 21 | 18 | 15
QST50 | 18 | 15 | 12
QST62 | 16 | 11 | 7
QST89/90 | 9 | 7 | 5

It is highly recommended that the mains supply chain is split if the number of tools exceed numbers in the table above.

The EMC certification is for one FlexCarrier.

The first mains power cable in one chain must be the Atlas Copco approved 32A cable. It is a critical part in the Safety certification.

Third party mains power supply

When a third party mains power supply is used it is required that another safety approved (UL 61010-1 or equivalent) mains switch is used. In that case it is recommended that the external fuse has the same value as for one power outlet, that is, a 30-32A slow blow fuse. However, if a smaller system is installed a 20A external fuse should be used.

The fuses in the FlexCarrier should always blow before any fuse installed before the FlexSystem.

Example

A 6-channel FlexSystem can be installed with a 20A external fuse.

If the Atlas Copco 32A mains cable is connected from the mains switch to the FlexCarrier, you do not necessarily need to have the same current rating for the cables feeding the factory installation system mains switch. The cable size should comply with the chosen fuse value.

In this Section

- Power distribution cable
- Power supply to mains switch box