Viessmann Vitomax HS M73 Operating And Service Instructions page 32

Repairs and inspection
Inspection
(cont.)
When inspecting the steam boiler and flues, only elec-
trical equipment provided for that purpose by the oper-
ator or their representative may be used. This equip-
ment including the connection cable and pipework
must conform to the relevant regulations.
Lamps must only be operated at safety voltages of
up to 42 V.
Inspections
The type and interval of the inspections depend on the
regulations that apply in the country of installation. The
Declaration of Conformity proposes that the system
should be tested at the following intervals:
32
The same regulations for hand-held electrical devices.
If lamps or hand-held devices are being fed from an
isolating transformer, higher voltages of up to 380 V
are permissible. Extra low voltage (ELV) and isolating
transformers must be located outside the steam boiler.
External test:
Internal test:
Repeated pressure
test:
Annually
Every 3 years
Every 9 years, max. test
pressure in accordance with
the initial pressure test