Chromalox NWHMT specifications General, Installation, Specifications Table a

Chromalox®

Installation, Operation

and

MAINTENANCE INSTRUCTIONS

SERVICE REFERENCE

DIVISION 4		SECTION NWHMT
SALES	(Supersedes PE439-1)		PE439-2
REFERENCE

161-303186-001

DATE APRIL, 1999

Type NWHMT Circulation Heater

(for Water Heating)

1-1/16” Dia. K.O. for 3/4” Conduit

Internal

Thermostat

1” Pipe

Outlet (Std.)

2 Mtg. Lugs ea. with two 3/8” - 16 x 1-1/2” deep holes on 1-1/4” centers

1” Pipe

Inlet (Std.)

	9-1/4”
3”
C	B	A
	3”

Specifications — Table A

Model	Volts	Phase	kW	W/In2	Dimensions (In.)
					A	B	C
NWHMT-3305	120, 240 or 480	1 or 3	3	50	21-5/8	9-3/8	—
NWHMT-3455	240 or 480	1 or 3	4.5	50	21-5/8	9-3/8	—
NWHMT-3605	240 or 480	1 or 3	6	50	34-3/4	22-1/2	16-1/2
NWHMT-3905	240 or 480	1 or 3	9	50	34-3/4	22-1/2	16-1/2
NWHMT-31205	240 or 480	1 or 3	12	50	57-1/2	45-1/4	39-1/4
NWHMT-31505	240 or 480	1 or 3	15	50	57-1/2	45-1/4	39-1/4
NWHMT-31805	240 or 480	1 or 3	18	50	57-1/2	45-1/4	39-1/4

3/8” NPT	7”
Pipe Plug

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.

Hazardous area terminal housings are available, consult your Local Chromalox representative for details.

The NWHMT series is a general-purpose water circulation heater intended for use indoors.

The three Copper sheathed tubular elements are centered in a 2- 1/2” diameter galvanized heating chamber and sealed in a removable screwplug. The assembly is surrounded by 1-1/2” insulation and sheet

metal jacket.

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

CAUTION: Users should install adequate back-up con- trols 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 the installation is the responsibility of the user, Chromalox will be glad to make equipment rec- ommendations.

INSTALLATION

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

1.Vertical mounting (axis of chamber vertical, see above drawing.) is preferred with terminal housing at top of heater (Figure 1).

2.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 (Figure 2).

3.The NWHMT series of circulation heaters are provided with mounting lugs to support the heater chamber. Refer to drawing above for location of these mounting lugs.

4.Mount heaters to permit unrestrained expansion of chamber due to temperature. This can be accomplished by using a slotted mount- ing assembly on either of the lugs.

Correct

Incorrect

Correct Incorrect

Figure 1 — Vertical Mounting

Figure 2 — Horizontal Mounting

© 2010 Chromalox, Inc.