In the case of star-shaped data bus networks, double
earthing is not permitted. The earthing must be carried
out on one side at the star point.
PE
L
H
+
Abschirmung
4-Draht-Bus
PE
Shielding
4-wire bus
Fig. 5:
Earthing for star-shaped data bus
• The outdoor sensor must not be mounted in the vicini-
ty of transmitters and receivers (on garage walls near
receivers for garage door openers, amateur radio an-
tennae, radio alarm installations or in the immediate
vicinity of large transmitters, etc.).
Maximum permitted cable lengths for cables carrying
sensor and low voltage (without PWM):
-
Min. 0.5 mm
2
-
Max. permitted cable length: 50 m
-
Max. PWM cable length according to pump specifi cation
Longer connecting cables should be avoided because of
the danger of radiated interference!
Inter-building installations
• Inter-building installations and laying the bus line under-
ground are not permitted
• Where possible, avoid routing low-voltage and safety
extra-low voltage cables (CAN bus line) in parallel in
adjacent buildings (overbuildings) or through under-
ground car parks. If this cannot be avoided, one or
more of the following options should be selected to im-
prove the decoupling:
- Increase the spacing distance
- Route cables in a metal cable tray or metal cable duct
that is enclosed on all sides, and must be well earthed
- Use high-quality twisted-pair cables
• Potential differences between CAN_H, CAN_L and
ground must be kept low
• If there are higher potential differences, the frequency
of errors will increase until the point when bus traffi c is
completely blocked
Advantage of an inter-building installation
- Bus modules can be connected together, communi-
cation of reference values
Disadvantages of an inter-building installation
- Increased susceptibility to interference, communica-
tion problems
- Voltage surge damage
To ensure correct electrical installation, unit connec-
tion and equipotential bonding (energy supply com-
pany and building installation), all applicable laws,
regulations and standards must be complied with;
in particular, the regulations of the responsible ener-
gy supply company. Common equipotential bonding
must be carried out in accordance with the regulati-
ons and standards. The cable shield is not allowed to
be used for equipotential bonding.
The work is only allowed to be carried out by quali-
fi ed specialist personnel. It is the responsibility of the
electrician to ensure appropriate EMC installation.
29
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INSTALLATION
Summary of Contents for UltraGas 15
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