Carrier 48AK, 48EW, 48EY024-068, 48AW, 48AY020-060 48A,E Series Staged Gas Implementation, Stages

IMPORTANT: Natural gas pressure at unit gas connection must not be less than 5 in. wg or greater than 13.5 in. wg.

Size gas-supply piping for 0.5-in. wg maximum pressure drop. Do not use supply pipe smaller than unit gas connection.

Fig. 23 — Field Gas Piping

OPTIONAL STAGED GAS UNITS — The staging pattern is selected based on Heat Stage Type (HTSTGTYP). Max Capacity per changes default value is selected based on Capac- ity Maximum Stage (CAPMXSTG). See Table 4.

For complete information and service instructions for Staged Gas Control Units, see Control Operation and Trouble- shooting literature.

Step 8 — Controls Options — The control options that the units can provide are based on the following parame- ters: CV (constant volume) or VAV (variable air volume) oper- ation; stand-alone unit with field-supplied sensors installed (CV or VAV); as a system via Carrier Comfort System (TEMP or VVT® [Variable Volume and Temperature]); optional elec- tronic expansion board installed (CV or VAV); linked to the Carrier Comfort Network; availability of a computer and soft- ware (ComfortWORKS® Building Supervisor, and Service Tool) or remote enhanced display accessory installed to access the base control board; and optional factory-installed staged gas control. See Table 5.

NOTE: Access to the base control board allows unit occu- pancy schedules, unit timeclock, and various set points to be changed from their factory-defined default settings.

Table 4 — 48A,E Series Staged Gas Implementation

NUMBER OF STAGES		MODEL NUMBER POSITION			POSITION		HEAT SIZE
	3		5	6,7,8	HTSTGTYP	CAPMXSTG
				024
				028
				030
	E		S	034	Default=1	Default=20	Low
				038
				044
				048
				020
				025
5 stages				027
	A		S	030	Default=1	Default=20	Low
				035
				040
				050
				038
	E		T	044	Default=1	Default=20	High
				048
				035
	A		T	040	Default=1	Default=20	High
				050
				024
	E		T	028	Default=2	Default=15	High
				030
7 stages				034
				020
	A		T	025	Default=2	Default=15	High
				027
				030
				054
	E		T	058	Default=3	Default=15	High
9 stages				064
				068
	A		T	060	Default=3	Default=15	High
				054
	E		S	058	Default=4	Default=15	Low
11 stages				064
				068
	A		S	060	Default=4	Default=15	Low

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