Check Power Supply Connection; Designating Heating Circuits; Setting High Altitude - Viessmann Vitocrossal 300 Service Manual

Vitocrossal 300 CU3A 26 to 57 Service

Check Power Supply Connection

An external accessories connection modules are
integrated into the Vitocrossal 300 CU3A boiler, which
requires a 120VAC power supply from a wall receptacle
(15A fuse protected).
Refer to the Installation Instructions shipped with the
boiler.
Voltage range
The voltage at connector 40 of the boiler control must be
120V (see wiring diagram).
Neutral conductor
The electrical power supply must have a neutral
conductor.

Designating Heating Circuits

Setting High Altitude

IMPORTANT
In Canada all electrical wiring is to be done in accordance
with the latest edition of CSA C22.1 Part 1 and/or local
codes. In the U.S. use the National Electrical Code ANSI/
NFPA 70. The heating contractor must also comply with
both the Standard for Controls and Safety Devices for
Automatically Fired Boilers, ANSI/ASME CSD-1.
Note: The line conductor "L " and the neutral conductor
"N" must not be interchanged.
See wiring diagram on page 94 in section entitled
"Additional Information".
In the delivered condition, the heating circuits are
designated "Heating circuit 1", "Heating circuit 2" and
"Heating circuit 3" (if installed).
If the system user prefers, the heating circuits can be
designated differently to suit the specific system.
To enter names for heating circuits:
Refer to the Operating Instructions
In the factory default setting, the boiler is equipped to
operate in altitudes of up to 5,000 ft. (1,500 m).
Altitude can be set using coding address 93:
(in coding level 2 General).
- Coding 11:9 must be set in order to unlock coding 93:.
- 93:0 is reserved for altitudes up to 5000 ft. (1500 m).
- 93:6 must be set for altitudes from 5000 ft. (1500 m).
to 10000 ft. (3000 m)
- Setting back to 93:0 turns off the high altitude
function.
IMPORTANT
Do not set or use coding addresses 93:1 to 93:5.
- After setting coding address 93:, set coding address 11:0
- The program is automatically disabled after 20 minutes.
Startup
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