Delta M50A-260 - Connecting the Grid (AC); General Information; Handling Aluminum Conductors During Installation Work

7 Installation
Connecting the grid (AC)
76
Installation and Operation Manual M50A_260 RPI503M260000 Product version L and M EU V1.3 EN 2023-08-14
7.8 Connecting the grid (AC)
► Always observe the information in section
“5.4 Planning the grid connection (AC)”,
page 37!
7.8.1 General information
180 mm
Fig. 7.8: Free space for wiring on the AC terminal block
Fig. 7.9: Torques for AC terminal block
20 mm20 mm
Fig. 7.10: Stripping length for AC cables
7.8.2 Handling aluminum conductors during
installation work
► The special properties of aluminum must be taken into con-
sideration when using aluminum conductors:
– Aluminum "ows," i.e. it gives way under pressure.
– A thin non-conductive oxide layer forms within a few
minutes on de-insulation, which increases the contact
resistance between the conductor and clamping point.
– The specic conductivity and hence the current carry-
ing capacity is approximately one third less than that of
copper.
NOTICE
To ensure a safe and reliable contact with alumi-
num conductors, always perform the following
work steps:
► Keep the installation location as free
as possible from moisture or corrosive
atmospheres.
► Connect the aluminum cables quickly.
► Clean the stripped end of the aluminum
conductor mechanically (for example,
using a knife blade to scrape o󰀨 the oxide
layer), then immediately dip the aluminum
conductor into acid-fee and alkaline-free (=
neutral) Vaseline and straight away insert it
into the Al-Cu compression joint.