Adjustments And Checkout - Honeywell C7076A Operating Instructions Manual

10.3 Making the connection
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1 Faceplate-aspirator
2 Front cover plate
3 Captive screws
4 Terminal block
5 Face plate
6 Connection for conduit
Before connecting the lead wires to the octal connector receptacle
block, completely remove the terminal block from the face plate to
be able to reach the terminal screws. See description below.
1 Open the master switch to interrupt all power to the detector.
2 Unlatch the detector and swing it away from the faceplate-aspi-
rator.
3 Loosen the four captive screws in the front cover plate (with the
viewing lens) and remove the plate.
4 Remove the 2 screws that hold the terminal block to the face
plate.
5 Run the wires from the flame safeguard control through the con-
duit to the terminal block.
6 Connect each wire to the proper terminal. Make sure not to
over-tighten the screws to avoid damaging the wire threads.
7 Remount the wired terminal block on to the face plate.
➔ IMPoRtAnt! Make sure that the electrical insulation remains
in the right place, to avoid short circuits against earth ground.
8 Reassemble the C7076 flame detector in the reverse order.

11 ADJUstMents AnD CHeCKoUt

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4
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11.1 Flame signal readings
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The final sighting position of the C7076A detector may be most
readily determined by using a test meter connected to the flame
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current meter jack on the plug-in electronics chassis. This output is
the unprocessed flame signal from the detector and is intended as a
diagnostic aid. Readings taken at the detector will facilitate installing
the detector in the best sighting position by pinpointing the region
of greatest UV intensity for a given flame.
Figure below illustrates the relationship between the detector and
amplifier readings. Detector saturation (the point at which an increase
in UV intensity does not product a noticeable increase in flame signal
strength) occurs at point A. Point B represents the point at which
the amplifier is saturated while the minimum UV sensitivity required
for system operation is at point C.
Comparison of UV intensity, amplifier saturation and detector saturation.
The linearity of the detector output curve shows that a unit increase
in UV intensity is accompanied by a corresponding increase in flame
signal strength. This condition facilitates pinpointing the location of
the most intense UV radiating from a flame. Thus, by locating the
optimum flame signal with the detector, the peak UV signal, and
therefore the most reliable reading, is obtained.
The minimum acceptable stable flame signal readings are:
– C7076A flame detectors: 1.4 µA.
– R7886 Flame Signal Amplifier: 1.2 V DC.
EN-8
WARnInG
Electrical shock hazard.
Can cause serious injury, death or equipment.
– Consult the burner/boiler manufacturer instructions and
sequence of operation for the burner management system
before initial burner lightoff.
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2
1
C
0
Amplifier Detector
saturation saturation
B A
Ultraviolet intensity