Thomas & Betts BE Uncrating and Preparation, Unit Heater Location, Clearances & Combustion Air

Size	M	N	P	R	S	T		U	W	…	X	Y	Z
	•	•	•	•	‚	‚		•	•		Hanger
25	94	532	481	133	273	214		375	157		793	249	76
50	94	532	481	133	273	214		375	157		793	249	76
75	69	532	481	133	324	214		375	157		793	265	76
100	44	532	481	133	375	214		375	157		793	265	76
125	34	532	481	133	521	214		521	157		908	294	67
165	72	659	641	184	445	291		521	202		932	297	117
200	34	659	641	184	521	291		521	202		932	297	117
250	150	1030	641	184	660	291		660	202		932	297	117
300	150	1030	641	184	660	291		660	202		932	297	91
400	172	1284	641	184	870	291		870	202		932	297	91
	•When equipped with optional blower cabinet.						…Use with 4-point suspension with blower cabinet.
NOTES	‚When equipped with optional duct flange.						†Contactor is standard on Models 300 and 400; optional on other
	ƒDimension includes a 3/4" flange on the rear of the blower						sizes.
	cabinet.						‡Contactor location with optional three phase motors on Sizes 50,
	„Use with 4-point suspension without blower cabinet. If						75, 100 and 125.
	installing hanger kit Option CK19, suspension points						ˆDeduct 6-5/8" on Sizes 50, 75, and 100 when equipped with
	change; see Paragraph 8.						direct drive motor.

4. Uncrating and Preparation

This unit was test operated and inspected at the factory prior to crat- ing and was in operating condition. If the heater has incurred any damage in shipment, file a claim with the transporting agency.

Check the rating plate for the gas specifications and electrical char- acteristics of the heater to be sure that they are compatible with the gas and electric supplies at the installation site. Read this booklet and become familiar with the installation requirements of your par- ticular heater. If you do not have knowledge of local requirements, check with the local gas company or any other local agencies who might have requirements concerning this installation. Before begin- ning, make preparations for necessary supplies, tools, and manpower. Check to see if there are any field-installed options that need to be assembled to the heater prior to installation. Each of the option pack- ages includes a list of components and step-by-step instructions. For a brief description of optional hanger kits, refer to Paragraph 8. For a brief explanation of other frequently specified field-installed options, see Paragraphs 25-31. After becoming familiar with the instructions, assemble and install the options that are required for your heater.

If the heater was ordered with a vent cap shipped with the heater (Option BT2), packaging depends on the size of the heater. Sizes 25 and 50 have the vent cap mounted on a shipping tube that is attached to the venter housing. Remove the vent cap; remove and discard the shipping tube. Sizes 100, 165, 200, 250, 300 and 400 have the vent cap attached directly to the venter housing. Size 125 is shipped with the vent cap mounted on the crate near the gas valve. Remove the vent cap for field installation at the vent terminal.

Unless the crate bottom has been removed for option installation, leave it attached until after the heater has been suspended. If the crate bottom has been removed, the bottom of the heater must be supported with plywood or appropriately placed boards. Without adequate support, the bottom access panel could be damaged.

To protect the unit during shipping, the blower model has special supports that must be removed before installation. Follow these in- structions to remove:

oBlower Support Legs -- Remove the two blower support legs and screws.

oMotor Shipping Block - Remove the wooden block located under the motor bracket. Find the two rubber pads shipped in the in- struction envelope. Place these pads on the ends of the motor bracket bolts.

oMotor Shipping Plate -- Blower models that are equipped with motors of 3/4 HP or less have a metal shipping plate attached between the motor and the blower housing. Remove and discard the shipping plate. Note: On units factory equipped with an optional belt guard, the belt guard must be removed in order to reach the shipping plate.

5. Unit Heater Location

CAUTION: Avoid installing a unit heater in extremely drafty areas. Extreme drafts can shorten the life of the heat exchanger and/or cause safety problems.

For best results, the heater should be placed with certain rules in mind. In general, a unit should be located from 8 to 12 feet above the floor. Units should always be arranged to blow toward or along exposed wall sur- faces, if possible. Where two or more units are installed in the same room, a general scheme of air circulation should be maintained for best results. Suspended heaters are most effective when located as close to the work- ing zone as possible, and this fact should be kept in mind when determin- ing the mounting heights to be used. However, care should be exercised to avoid directing the discharged air directly on the room occupants.

Partitions, columns, counters, or other obstructions should be taken into consideration when locating the unit heater so that a minimum quantity of airflow will be deflected by such obstacles.

When units are located in the center of the space to be heated, the air should be discharged toward the exposed walls. In large areas, units should be located to discharge air along exposed walls with extra units provided to discharge air in toward the center of the area.

At those points where infiltration of cold air is excessive, such as at en- trance doors and shipping doors, it is desirable to locate the unit so that it will discharge directly toward the source of cold air from a distance of 15 to 20 feet.

Units should not be installed closer than 18 inches from any wall.

CAUTION: Do not locate the heater where it may be exposed to water spray, rain or dripping water.

6. Clearances & Combustion Air

Units must be installed so that the following clearances are provided for combustion air space, service and inspection, and for proper spacing from combustible construction.

Mfg P/N 98807 Rev 8, Page 5