User Manual

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Building Technologiesn CC1N7491.1en
03.04.2018
Installation notes
The LMU34 cannot be operated on isolated networks (with no reference to ground)
The high limit thermostat (TB) must be short-circuit proof and adequately secured
in its position
Do not mix up live and neutral conductors (only LMU34.300)
Install switches, fuses and earthing, in compliance with local regulations
Make certain that the maximum permissible current rating of the connection termi-
nals is not exceeded
When wiring the unit, ensure that mains voltage and protective extra low-voltage
are always strictly separated to warrant protection against electrical shock hazard
(according to DIN EN 60730-2-5)!
Only use high-quality and heat-resistant earthing cable
On the application, it must be ensured that the connections for functional earth
(burner ground) are connected to protective earth with low impedance
The process-related connections (X300, X400, and X401) are segregated from
mains supply by double or reinforced isolation and powered by protective extra
low-voltage (PELV) via a safety isolating transformer. For the PWM fan output
(X401: Pin 7 / 8) and the Hall sensor input (X401: Pin 5 / 6), double or reinforced
isolation against active live parts must be ensured on the application itself
Ensure that the level of protection against electrical shock hazard will not be re-
duced when installing or integrating the unit into the equipment
When making the boiler isolation test, functional earth (X500 / X900) must be con-
nected. If not, isolation on the LMU34 will not be tested
Use of high-efficiency pumps
When using high-efficiency pumps or pumps with integrated electronics, the resulting
switch-on currents can adversely affect the relays’ service life. For this reason, use of
these types of pump is permitted only if previously authorized in writing by
Siemens AG.
Attention!
High-efficiency pumps or pumps with integrated electronics connected to the
AGU2.005 may include overvoltage protection switching circuits which can
affect the behavior of the system in terms of EMC.
These overvoltage protection switching circuits can also result in high cur-
rents that overload the relay contact of the AGU2.005.
The overvoltage protection system must be suitably designed by the system
integrator to prevent the relay contact from being overloaded.
Operation of the AGU2.005 is only permitted as shown in the connection dia-
gram (see Data Sheet N7216 / N7217).