Chromalox NWHO-33015 specifications General, Installation, Thermostat Specifications - Table A

Chromalox®
Installation	SERVICE REFERENCE
and	DIVISION 4		SECTION NHWO
	SALES	(Supersedes PE406-4) PE406-5
RENEWAL PARTS IDENTIFICATION	REFERENCE
		161-048710-001

1-3/8” Conduit				DATE	FEBRUARY, 1999
		12-5/16”
Openings
1” Pipe	8-1/32”	Type NWHO-3 Series Circulation Heaters
Outlet		(for Regular and Fuel Oil Heating)
		Thermostat Specifications — Table A
		Type AR			Regular Oil Heaters
A	B C	Mounting Lugs						Dimensions (In.)
		3/8” - 16	Model	Volts	Phase	kW	W/In2	A	B	C
		Threaded Holes -
		1-1/2” Deep	NWHO-33015			3		32-15/16	22-1/2	16-1/2
		1-1/4” Centers
			NWHO-34515			4.5		32-15/16	22-1/2	16-1/2
			NWHO-36015	240 or 480	1 or 3 s	6	23	42-15/16	32-1/2	26-1/2
			NWHO-37515			7.5		55-7/16	45	39
			NWHO-39015			9		55-7/16	45	39
					Fuel Oil Heaters
1” Pipe			NWHO-30315			3		32-15/16	22-1/2	16-1/2
Inlet
			NWHO-30415	240 or 480	1 or 3 s	4	15	42-15/16	32-1/2	26-1/2
			NWHO-30615			6		55-7/16	45	39
		6-1/8”

GENERAL

WARNING: This heater is not intended for use in haz- ardous atmospheres where flammable vapors, gases, liquids or other combustible atmospheres are present as defined in the National Electrical Code. Failure to comply can result in explosion or fire.

The NWHO-3 series is a general-purpose regular and fuel oil solu- tion circulation heater intended for use indoors. It is designed for 150 psig at 550˚F per ANSI standards.

The 3 steel-sheathed tubular elements are centered in a 3” diame- ter steel heating chamber and welded to a removable steel flange. The assembly is surrounded by 1-1/2” insulation and sheet metal jacket.

Depending upon the order specifications, the NWHO-3 may or may not be factory equipped with AR or other Chromalox thermostat. Such thermostats function to control outlet temperatures and to limit internal temperatures under abnormal flow conditions. These controls do not fail safe.

CAUTION: Users should install adequate back-up controls and safety devices with their electric heating equipment. Where the consequences of failure may be severe, back- up controls are essential. Although the safety of installa- tion is the responsibility of the user, Chromalox will be glad to make equipment recommendations.

INSTALLATION

WARNING: Hazard of Shock. Disconnect all power before installing heater.

1.Vertical mounting (Preferred) —

When the heater is vertically mounted, the terminal housing will be at the top of the heater. The inlet pipe will be located on the side near the bottom of the heater and the outlet pipe at the top.

The axis of the chamber will be in a vertical position as in the photo above and as in Figure A.

Note: A drain pipe located at the bottom of the heater should be provided and enough room left, when mounting heater, to allow draining the heater.

2.Horizontal Mounting (Optional) —

When mounting heater horizontally, inlet and outlet pipes must be up. In any other position, heater cannot be purged of air, and ele- ments may be seriously damaged. (See Figure B.)

Correct

Incorrect

CorrectIncorrect

Figure A — Vertical Mounting

Figure B — Horizontal Mounting

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