Carrier 48EZ(N)-A Check Gas Input, Adjust Gas Input, Altitude Derate Multiplier for U.S.A

integrated gas unit controller (IGC) has the capability to automatically reduce the evaporator “ON” delay and in- crease the evaporator “OFF” delay in the event of high duct static and/or partially-clogged filter.

Check Gas Input

Check gas input and manifold pressure after unit start-up (See Table 3). If adjustment is required proceed as follows:

SThe rated gas inputs shown in Table 3 are for altitudes from sea level to 2000 ft (610 m) above sea level. These inputs are based on natural gas with a heating value of 1025 Btu/ft3 at 0.60 specific gravity, or propane gas with a heating value of 2500 Btu/ft3 at 1.5 specific gravity.

IN THE U.S.A.:

The input rating for altitudes above 2,000 ft (610 m) must be reduced by 4% for each 1,000 ft (305 m) above sea level.

For installations below 2,000 ft (610 m), refer to the unit rating plate.

For installations above 2,000 ft (610 m) multiply the input by on the rating plate by the derate multiplier in Table 4 for correct input rate.

Table 4 – Altitude Derate Multiplier for U.S.A.*

ALTITUDE FT (M)		PERCENT OF DERATE	DERATE MULTIPLIER
			FACTOR{
0---2000		0	1.00
(0---610)
2001---3000*		8--- 12	0.90
(610	---914)
3001	---4000	12--- 16	0.86
(315---1219)
4001	---5000	16--- 20	0.82
(1220	---1524)
5001	---6000	20--- 24	0.78
(1524	---1829)
6001	---7000	24--- 28	0.74
(1829	---2134)
7001	---8000	28--- 32	0.70
(2134	---2438)
8001	---9000	32--- 36	0.66
(2439	---2743)
9001---10,000		36--- 40	0.62
(2744	---3048)

*In Canada see Canadian Altitude Adjustment.

{Derate multiplier factors are based on midpoint altitude for altitude range.

BURNER FLAME

BURNER

MANIFOLD

C99021

Fig. 10 - Monoport Burner

IN CANADA:

The input rating for altitudes from 2,000 to 4,500 ft (610 m to 1372 m) above sea level must be derated 10% by an authorized Gas Conversion Station or Dealer.

EXAMPLE:

90,000 Btu/hr Input Furnace Installed at 4300 ft (1311 m).

Furnace Input Rate at	X	Derate Multiplier	=	Furnace Input Rate at
Sea Level		Factor		Installation Altitude
90,000	X	0.90	=	81,000

When the gas supply being used has a different heating value or specific gravity, refer to national and local codes, or contact your distributor to determine the required orifice size.

	!		CAUTION
		UNIT DAMAGE HAZARD
		Failure to follow this caution may result in reduced unit
		and/or component life.
		Do Not redrill	an orifice. Improper drilling (burrs,
		out-of-round holes, etc.) can cause excessive burner noise
		and misdirection of burner flame. If orifice hole appears
		damaged or it is suspected to have been redrilled, check
		orifice hole with a numbered drill bit of correct size.
Adjust Gas Input
The gas input to the unit is determined by measuring the gas flow
at the meter or by measuring the manifold pressure. Measuring the
gas flow at the meter is recommended for natural gas units. The
				A
manifold pressure must be measured to determine the input of
				--
propane gas units.
				48EZ
Measure Gas Flow (Natural Gas Units)
Minor adjustment to the gas flow can be made by changing the
manifold pressure. The manifold pressure must be maintained
between 3.2 and 3.8 IN. W.C.
If larger adjustments are required, change main burner orifices
following the recommendations of national and local codes.
NOTE: All other appliances that use the same meter must be
turned off when gas flow is measured at the meter.
Proceed as follows:

1.Turn off gas supply to unit.

2.Remove pipe plug on manifold (See Fig. 11) and connect manometer. Turn on gas supply to unit.

3.Record number of seconds for gas meter test dial to make one revolution.

4.Divide number of seconds in Step 3 into 3600 (number of seconds in one hr).

Pipe Plug Manifold

A07679

Fig. 11 - Burner Assembly

5.Multiply result of Step 4 by the number of cubic feet (cu ft) shown for one revolution of test dial to obtain cubic feet (cu ft) of gas flow per hour.

6.Multiply result of Step 5 by Btu heating value of gas to obtain total measured input in Btuh. Compare this value with heating input shown in Table 3 (Consult the local gas supplier if the heating value of gas is not known).

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