Application Note S4565Df, Tf With External Main Burner Interrupt - Honeywell S4565 Production Handbook

APPLICATION NOTE S4565DF, TF WITH EXTERNAL MAIN BURNER INTERRUPT

Side connections**
Fig. 47. Connection diagram S4565DF, TF with external main burner interrupt in fan assisted applications
External main burner interrupt
Maximum open contact voltage 24 V
Maximum current 15 mA
A low voltage relay is suitable.
An opto coupler e.g. CNY17-3 is also possible
A flame indicating series LED (see Fig. 49.) will conduct
minimal 0.85 mA if the contact is open and will conduct
minimal 3.5 mA if the contact is closed.
Suffix DF and TF in fan assisted applications (see Fig. 48.)
When there is a call for heat the fan starts running through
the no air position of the air proving switch after a self check
period (T ) plus a waiting period (T
c
starts after fan is switched on).
When sufficient air flow is proven by the air proving switch,
the built-in igniter and pilot gas valve are switched on.
The ignition spark ignites pilot gas and resulting flame is
detected by the flame rod.
12 11 10
LM
N L
) (* = The safety time
w*
9 8 7 6
CNY 17-3
P
* See note 17.
** Alternative side connection for models with combined flame
detection/high voltage. See page 56. Fig. 71.
Ignition is switched off after a predetermined extended
ignition time T(
main valve is switched on.
If flame is not established within the safety time (T
ignition control locks out.
If the flame is lost during normal run, the ignition control
repeats start sequence.
If no air is proven by the air proving switch within the safety
time (T ), the ignition control locks out.
s
If the internal main burner interrupt is activated (relay contact
opened or opto transistor de-activated) the main valve drops
off, but the pilot flame stays present.
Suffix DF and TF in atmospheric applications (see Fig. 50.)
When there is a call for heat ignition starts immediately after
the self check period (T
39
3
5 4
Optional
) and flame establishment and then the
ext
) plus a waiting period (T
c
EN2R-9031 0402R15-NE
2 1
*
RS
), the
s
).
w