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Rittal air/water heat exchanger assembly instructions
4 Assembly and connection
EN
4.6.3 Door limit switch
– Each door limit switch must only be assigned to
one air/water heat exchanger.
– Several door limit switches may be connected
in parallel and operated on one air/water heat
exchanger.
– The minimum cross-section of the connection
cable is 0.3 mm
2
for a cable length of 2 m.
We recommend the use of a shielded cable.
– The line resistance to the door limit switch must not
exceed a maximum of 50
Ω
.
– The door limit switch only supports a floating
connection; no external voltages.
– The contact of the door limit switch must be closed
when the door is open.
The safety extra-low voltage for the door limit switch
is provided by the internal power pack: Current
approx. 30 mA DC.
• Connect the door limit switch to terminals 1 and 2
of the connector.
4.6.4 Notes on the flicker standard
The flicker limits specified in standard EN 61 000-
3-3 or -3-11 are adhered to, provided the supply
impedance is less than approx. 1.5
Ω
.
Where necessary, the unit operator should measure
the connected impedance or consult the responsible
power supply company. If there is no way of influenc-
ing the supply impedance and sensitive installed
components (e.g. BUS) are subjected to interfer-
ence, a line reactor or starting-current limiting device
should be connected upstream of the air/water heat
exchanger to restrict the startup current of the air/
water heat exchanger.
4.6.5 Potential equalisation
Rittal recommends connecting a conductor with a
nominal cross-section of at least 6 mm
2
to the poten-
tial equalisation connection point on roof-mounted
air/water heat exchangers and incorporating it into
the existing potential equalisation system. According
to the standard, the PE conductor in the mains con-
nection cable is not classified as an equipotential
bonding conductor.
Summary of Contents for SK 3209. Series
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