Mechanical Design - Siemens LMG2 Series Manual

Electrical connection of
ionization current and UV
detectors

Mechanical design

Burner controls LMG2...
Plug-in base
Landis & Staefa Division
It is important to achieve practically loss-free signal transmission
• Cable length may not exceed 20 m
• Never run the detector cable together with other cables
– Line capacitances reduce the magnitude of the flame signal
– Use a separate cable
• Insulation resistance
– Between detector electrode and ground: minimum 50 MΩ
– Soiled detector electrode holders reduce insulation resistance, thus supporting
creepage currents
• Earth the burner in compliance with the relevant regulations; earthing the boiler alone
does not suffice
• Observe the polarity
Burner controls LMG2... detect wrong polarity of live and neutral, in which case they
initiate lockout at the end of «TSA»
– Plug-in design like predecessor type LGB2... (refer to «Dimensions»)
– Housing made of impact-proof, heat-resistant plastic
– Housing accommodates the
- control of the microcontroller with PCB relay for load control
- electronic flame signal amplifier (ionization)
- lockout reset button with integrated red fault indication lamp and green flame signal
lamp
– Made of impact-proof, heat-resistant plastic
– Available with screw terminals AGK11
– Cable entry optionally
- from the front or laterally by means of cable gland holders AGK65 or cable holders
AGK66
- from below through two holes of 16.2 mm dia.
– Provided with catches on the two narrow sides which engage in the burner control's
housing
- must audibly click when plugging in the LMG2...
- to disengage, a screwdriver must be slightly tilted in the guiding slots; then, the
burner control slightly lifts
– For length and width of plug-in base and positions of fixing holes, refer to
«Dimensions»
CC1N7421E December 04, 1998 3/16