NTI FTG 2000, Инструкция по эксплуатации, Страница: 5 / 6

5
Table 2-2 Minimum and Maximum Modulation Rates
Model Min. Modulation Rate (RPM) Max. Modulation Rate (RPM)
Input Rate (MBH)
Min Max
1
FTG 2000 1050 7100 235 2000
FTG 2200 1050 7200 235 2200
FTG 2400 1050 8000 235 2350
Notes:
1
Canada: Altitudes between 2000-4500 ft, de-rate by 10%. Consult local authorities for de-rating for altitudes above 4500ft.
2
Use Diagnostic Test , accessed from the Diagnostic menu of the display, to force max. and min. modulation rates; see
Appendix A – Controller and Touchscreen Display Instructions, Section 5 DIAGNOSTICS PAGE.
Figure 2-1 Gas Valve Offset Check/Adjustment
Differential Pressure
Manometer
–
min. graduation
of 0.01 in. w.c (1 Pa)
Offset Adjustment Procedure:
1) Differential Pressure Manometer
– obtain a
meter capable of measuring differential
pressure (“+” and “-“ ports) with a minimum
graduation of 0.01 inches w.c. (or 1 Pa).
2) Installation
– with the burner off, remove the
caps from the pressure tappings. Connect
the Feedback Pressure Tapping to the
Positive (+) port of the manometer; connect
the Manifold Pressure Tapping to the
Negative (-) port of the manometer. Verify
that the manometer is reading zero
– zero the
meter if necessary.
3) Calibrate Combustion
– operate burner to
maximum modulation rate (see Table 2-2),
ensuring gas line pressure is maintained
above 4 inches w.c.; set combustion
according to Table 2-1 using the Throttle
Screw
– record CO
2
value.
4) Set Offset
– operate burner to minimum
modulation rate (see Table 2-2); set offset
pressure according to Table 2-1 using the
Offset Screw.
NOTICE
:
Since the Manifold Pressure Tapping
is connected to the Negative (-) port of the
manometer, a negative Offset Pressure will
read positive; e.g., to achieve an offset
pressure of -0.03, manometer will read +0.03.
5) Verify Combustion
– with the burner
remaining in operation at the minimum
modulation rate, measure combustion and
compare to readings obtained during
maximum modulation
– CO
2
must be 0.5 to
1.0% lower at minimum modulation. If
readings are out of tolerance
– CONTACT
NTI FOR ASSISTANCE.
6) Complete Test
– shutdown the burner,
remove the manometer tubing and reinstall
the factory caps on Offset Pressure Tappings.
Positive (+)
Negative (-)
Feedback
Pressure
Manifold
Pressure
Throttle Screw
Used to calibrate combustion at max.
modulation rate (use slot screw driver)
Offset Screw
– used to set offset and
combustion at min. modulation rate.
Follow directions on screw
– minus reduces
offset/CO
2
(use 2.5 mm hex wrench)