Honeywell TC Series

TC · Edition 08.17 26
Function
3.1.7 Test instant for Mode 3: testing before and after
burner run
t
M
5s
10s
15s
20s
25s
30s
Mode 3
The first test is carried out before burner run (as with
Mode 1):
The tightness test starts with incoming thermostat/
start-up signal ϑ. If the valves are tight, the LEDs
1
2
Power
and
1
2
Power
are green. Once the safety interlock input
signal
OK
V1
V2
is active, the OK enable signal is forwarded to
the automatic burner control unit, see page 24 (Test
instant for Mode 1: testing before burner run).
The second test is carried out after burner run (as with
Mode 2):
The tightness test after burner run starts when the
thermostat/start-up signal ϑ drops, see page 25
(Test instant for Mode 2: testing after burner run).