Manual

9
Application notes:
1) The DC
µ
A function is designed especially for HVAC/R flame sensor applications.
The 0.1
µ
A resolution is useful for identifying the minute current changes in flame
detector applications. Flame signal current check should indicate steady flame
signal of at least 2
µ
A for a rectification type, 1.5
µ
A for an ultraviolet type, or 8
µ
A
for self-checking systems. If a flame signal current with inadequate strength or
fluctuation beyond 10%, check the following to avoid the risk of unwanted flame
relay dropout:
1.1) For gas or oil flames (Minipeeper):
z Low supply voltage
z Detector location
z Defective detector wiring
z Dirty viewing windows
z Faulty Minipeeper
1.2) For oil flames (Photocell):
z Detector location & wiring
z Smoky flame or poorly adjusted air shutter
z Faulty Photocell
z Temperature over 165°F (74°C) at photocell
1.3) For gas flames (Flame Rod):
z Ignition interference (A flame signal current difference with the ignition both on
and off greater than 0.5
µ
A indicates the presence of ignition interference)
z Insufficient ground (must be at least 4 times the detector area)
z Flame lifting off burner head (ground), or not continuously in contact with the
flame rod
z Temperature in excess of 600°F (316°C) at the flame electrode insulator,
causing short to ground.
HOLD
The hold feature freezes the upper ACA display for later viewing. Press the HOLD
button momentarily to activate or exit this feature.
MAX
The Max feature compares and displays the measured maximum value (on the upper
ACA display) as fast as 25ms with auto-ranging capability. Press the MAX button for 1
second or more to activate or exit this feature.