User Manual

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Building Technologies Division CC1N7491en
18.07.2018
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
∂ Install switches, fuses and earthing, in compliance with local regulations
∂ Make certain that the maximum permissible current rating of the connection
terminals 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 (X400, X401, X700 and X800) 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 5 / 6 / 7 / 8) and PWM pump output (X700), 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
reduced when installing or integrating the unit into the equipment
∂ When making the boiler isolation test, functional earth (X500 / X900) must be
connected. 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 currents
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
diagram (see Data Sheet N7216).