Man_E_230_21y_0z_man_s2.8x_rev0_SIL3.doc
© 2005 –2008 M.M.T. Srl pag. 6/23
4 - General Safety information
Safe use of the product depends on correct installation. All necessary operations and interventions on this
machine must be performed by a qualified technician, according to the operating instructions.
Qualified technicians are people that have:
- knowledge of electrical engineering
- knowledge of electric safety regulations
- knowledge of accident prevention
It is important to follow general instructions, safety installation procedures and safety regulations for thermal
and electric plants, and use all the tools and safety equipment properly.
The product has been designed and produced to withstand conditions encountered during normal use.
The use of the product for any other purpose, or failing its proper installation, or not following the instructions,
can cause damage to the product, can invalidate its CE marking, and can cause serious injuries or death to people,
things and the environment.
The level probe and the level switch are only a part of the safety chain.
To complete the safety chain, additional devices are required, such as wirings, relays, bells, lamps, and actuation
devices.
The chain has to be designed and built to be fail-safe.
In case of fire in the environment, seismic events or adverse atmospheric events (wind), the correct working of
the safety accessory is no longer guaranteed.
In these cases, the power supply must be immediately shut off from the safety accessory; and the probe, the level
switch and the cable between them must be checked by a qualified technician.
Only after having verified that the accessory is not damaged, can the power supply be reconnected.
4.1 Probe
All the operations on the probe must always be done exclusively by a qualified technician.
The operations on the probe must always be done when the boiler is not pressurized and cold.
Remember that a boiler can remain at a high temperature also for a long time after depressurization.
Contact the manufacturer of the boiler for information about the water alarm level.
Consider carefully that in some cases, the water level in the boiler may be different from the external indicator.
The electrode needs to be positioned at least 14 mm from the protection tube (if present), or from the sides of the
boiler.
Do not install the probe in the open air without suitable protection against atmospheric agents.
The vent and drain holes must always be free and clear, and never covered.
4.2 Level switch
Always entrust all the operations on the level switch exclusively to a qualified technician.
Operations on the level switch must always be performed when the power supply is shut off, because dangerous
voltages may be present inside the level switch.
Before performing any operation or test on the safety accessory, the technician must be electrostatically
discharged to avoid damaging the equipment.
The power supply must be protected against the risk of short circuits or overcurrent by a suitable system
according to the construction standard of the electric cabinet and plant, to enable easy maintenance, service, and
repair.
