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5790 733 - 07
Vitocrossal 300 CA3 Series 2.5 to 6.0 Installation/Service
General Service Information
Checking the high limit safety cut-out setting
The high limit safety cut-out is preset to 210°F (99°C).
If this temperature needs to be changed, this can only
be done by changing the coding card.
Refer to the control section of the Installation
Instructions.
■
Shut down the heating system.
■
Ventilate boiler room.
■
Close all doors in the living space
Working on the system
■
Where gas is used as the fuel, close the main gas
shut-off valve and safeguard it against unintentional
reopening.
■
Isolate the system from the power supply (e.g. at the
separate fuse or a main switch) and check that it is
de-energized.
■
Safeguard the system against reconnection.
Target group
These instructions are intended exclusively for qualified
contractors.
■
Work on gas installations must only be carried out
by a licensed professional heating contractor.
■
Work on electrical equipment must only be carried
out by a qualified electrician.
■
The system must be commissioned by the system
installer or a qualified person authorised by the installer.
■
This appliance has not been designed to be operated
by individuals other than those qualified and trained.
Regulations
Observe the following when working on this system:
■
Statutory regulations regarding the prevention of accidents
■
Statutory regulations regarding environmental protection
■
Codes of practice of the relevant trade associations.
If you smell gas
Safety Instructions
■
Do not smoke. Prevent naked flames and sparks. Do not
press any switches for lights or electrical appliances.
■
Close the gas shut-off valve.
■
Open windows and doors.
■
Remove all people from the danger zone.
■
Notify your gas or electricity supply utility from outside
the building.
■
Shut off the electricity supply to the building from a
safe place (outside the building).
If you smell flue gas
WARNING
Escaping gas can lead to explosions which may result
in serious injury.
WARNING
Flue gas can lead to life threatening poisoning.
Auxiliary components, spare and wearing parts
Note:
Spare and wearing parts that have not been tested
together with the system can compromise its function.
Installing non-authorised components and making
non-approved modifications or conversions can
compromise safety and may invalidate our warranty.
For replacements, use only original spare parts
supplied or approved by Viessmann.
Note:
Electronic assemblies can be damaged by
electrostatic discharges. Before beginning work,
touch grounded objects, such as heating or water
pipes, to discharge static loads.
CSD-1 Field Testing of High Limit Switches for Vitocrossal
300, CA3 boilers – where required by law.
As per ASME Boiler and Pressure Vessel Code, section IV,
subsection HG-613 TEMPERATURE CONTROL
requirements, Vitocrossal 300, CA3 hot water boilers are
protected from over-temperature by two temperature-
operated controls. These temperature control devices
conform to Standards for Limit Controls, and are accepted
by CSA, a nationally recognized testing agency.
Each boiler is equipped with a manual reset high
temperature limit control and a temperature control that
will cut off fuel supply when the system water
temperature reaches a preset operating temperature.
VIESSMANN IS NOT RESPONSIBLE FOR ANY DAMAGES
THAT THE FOLLOWING TEST PROCEDURE MAY RESULT
IN BY OVERHEATING THE SYSTEM.
The Vitocrossal 300, CA3 boilers are equipped with 2 RTD
temperature sensors (per boiler section) that when activat-
ed on temperature rise (high fixed limit of 210°F (99°C)
disable the burners to operate.
The fixed high limit, when tripped, produces a fault that
will require manual reset of the boiler control.
Repair work
Note:
Repairing components that fulfil a safety function
can compromise the safe operation of your system.
Replace faulty components only with original
Viessmann spare parts.
