11
Eclipse TFB, V2, Design Guide 310, 11/14/2014
Figure 3.9. System Schematics
Step 3: Ignition System
For the ignition system use:
• 6000 VAC transformers
• full wave spark transformers
• one transformer per burner
Do NOT use:
• 10,000 VAC transformers
• twin outlet transformers
• distributor type transformers
• half wave spark transformers
TFB burners are capable of direct spark ignition anywhere
within the listed operating range. However, it is
recommended that low fire start be used. Local safety and
insurance requirements demand that you limit the
maximum time that a burner takes to ignite. These time
limits vary from country to country. For the USA the time
limit is 15 seconds, for Europe it is 3 seconds.
The time that a burner takes to ignite depends on:
• the distance between the gas shut-off valve and the
burner
• the air/gas ratio
• the gas flow at start conditions
In the USA, with a time of 15 seconds to ignition, there
should be sufficient time to ignite the burners. It is
possible, however, to have the low fire too low to ignite
within the time limit. Under these circumstances you must
consider the following options:
• start at higher input levels
• resize and/or relocate the gas controls
Step 4: Flame Monitoring Control System
A flame monitoring system consists of two main parts:
• a flame sensor
• flame monitoring control
NOTE:
A flame monitoring system may not be required for
tube fired burners. According to NFPA 86, combustion
safeguards on radiant tube type heating systems are not
required where a means of ignition is provided and the
systems are arranged and designed such that either of the
following conditions is satisfied:
(a) The tubes are of metal construction and open at one or
both ends with heat recovery systems, if used, that are of
explosion-resistant construction.
(b) The entire radiant tube heating system, including any
associated heat recovery system, is of explosion-resistant
construction.
P
Combustion air at ambient temperature
(Radiant & Immersion applications)
P
Pre-heated combustion air
(Radiant applications)
Safety
Valve
Train
Safety
Valve
Train
to other Burners
Impulse line
Pressure taps
to other Zones
to other Zones
to other Burners
to other Burners
to other Burners
Impulse line
Pressure taps
to other Zones
to other Zones
(optional)
(optional)