Lochinvar MT Installation Manual

Industrial Screw Plug Immersion Heaters

ARMT, ARMTO, ARMTS, ARMTI, AREMTI, AREMTO,

AREMTS, CH-SD, EMT, EMTI, EMTO, EMTS, E4TP,

MT, MTI, MTO, MTS, ARTM, ARTMO, ARTMS & ARTMI

Note: These instructions relate to all enclosure styles shown within.

DIVISION 4 SECTION

MT

SALES

REFERENCE

DATE

SERVICE REFERENCE

161-048381-001

AUGUST, 2009

PD407-18

Chromalox

®

(Supersedes PD407-17)

Installation, Operation

and

MAINTENANCE INSTRUCTIONS

© 2010 Chromalox®, Inc

Type E4 Terminal Enclosure

Moisture Resistant

NEW Type E4TP Terminal Enclosure

Type E1 Terminal Enclosure

General Purpose (Rotatable)

Type E2 Terminal Enclosure

Explosion Resistant/Moisture Resistant

Chromalox type ARMT, ARMTO, ARMTS, ARMTI,
AREMTI, AREMTO, AREMTS, CH-SD, EMT, EMTI, EMTO,
EMTS, E4TP, MT, MTI, MTO, MTS ARTM, ARTMO, ARTMS
and ARTMI screw plug immersion heaters are designed for a wide
variety of heating applications.

Heater Construction Characteristics:

A. High quality resistance wire held in place by compacted

Magnesium Oxide Refractory enclosed in a wide variety of
sheath materials.

B. Low to high watt densities.
C. Standard selection of sheath materials include copper, steel,

INCOLOY

®

alloy and stainless steel. This broad selection of
sheath materials will operate successfully in many corrosive
solutions.

D. Proper selection of sheath material is the sole responsibility of

the customer.

E. Units are available with E1 General Purpose, E4 Moisture

Resistant and E2/E3 Explosion/Moisture-Resistant terminal
enclosures.
Additional enclosure styles available but not shown above.

IMPORTANT: It is the responsibility of the purchaser of
the heater to make the ultimate choice of sheath
material based upon his/her knowledge of the chemi­cal composition of the corrosive solution, character of
the materials entering the solution, and controls
which he/she maintains on the process.

Sheath corrosion can result in a ground fault
which, depending upon the solution being heated,
can cause an explosion or fire.

The system designer is responsible for the safety of
this equipment and should install adequate back-up
controls and safety devices with their electric heating
equipment. Where the consequences of failure could
result in personal injury or property damage, back-up
controls are essential.

FIRE HAZARD. An integral thermostat, if provided, is
designed for temperature control service only.
Because the thermostat does not fail safe, it should
not be used for temperature limiting duty. Wiring to
this device is the responsibility of the user.

GENERAL

INSTALLATION

ELECTRIC SHOCK HAZARD. Disconnect all power
before installing or servicing heater. Failure to do so
could result in personal injury or property damage.
Heater must be installed by a qualified person in accor­dance with the National Electrical Code, NFPA 70.

1. Before installing, unpack and check your immersion heater for any

damage that may have occurred during shipment. Report any
claims to your carrier if damage has ocurred in shipment. Do not

operate damaged equipment. Consult factory for
instructions.

2. Check to ensure that the line voltage is the same as that stamped

on the nameplate. Verify wattage and capacity versus the require­ments at installation site.

3. Do not bend the heating elements. If bending is necessary,

consult factory.

4. IMPORTANT: Mount the heater in the tank so that the liquid

level will always be above the effective heated portion of the
heater. If the heater is not properly submerged, it may overheat and
damage the heating elements (see Figure 1).

5. Where work will pass over or near equipment, additional protection

such as a metal guard may be needed.

6. Heater shall not be operated in sludge.

FIRE HAZARD. If the heater is not properly sub­merged, the heating elements will overheat and could
result in a fire or damaged equipment.

7. Install the heater using a high quality pipe sealing compound on the

threads. Screw the heater into the opening (Figure 2). Tighten suf­ficiently with wrench applied on the hex portion of the screwplug.

8. Closed Tank Installation

EXPLOSION HAZARD. When heating in closed vessels,
controls and back-up controls must be used to regu­late build-up of temperature and/or pressure.

A. Horizontal Position (Figure 3)

A1. Place heater at an elevation so that natural circulation can

take place.

A2. Position outlet and inlet in a vertical plane, facing upward

to prevent air pockets. Be sure all trapped air is removed
from the closed tank. Bleed the air out of the liquid piping
system and heater enclosure prior to operation.

A3. IMPORTANT: Heater should never be located at the high-

est point of the liquid system. Provide expansion tank, if
necessary.

A4. Heater shall be supported if the immersion length is greater

than 36”.

FREEZE HAZARD. This unit may be equipped with a
thermowell for process control or over-temperature
control. Do not allow moisture to accumulate in ther­mowell. Freezing temperatures can cause damage
that my result in the heated medium leaking into ter­minal closure.

B. Vertical Position (Figure 4)

A drip loop is recommended to minimize passage of moisture from
condensation along wiring into terminal enclosure and connections.

9. To prevent moisture accumulation in cryogenic applications or

when heater is exposed to freezing temperatures:

A. Slope conduit away from enclosure (drip loop).
B. Seal all conduit openings to moisture/explosion resistant termi-

nal enclosure.

C. Insulate terminal enclosure.
D. Fill thermowell(s) with silicone, fluid when heater is mounted

with terminal enclosure up.

Note: Locate Heater as low as possible for maximum heated liquid storage

capacity. Heat does not move downward.

Figure 1 - Open Tank Installation

Expected Low Liquid

Level

This Portion of the Heater Above Liquid Level and

Exposed to Air Will Lead to Premature Burnout of Element

Expected Maximum

Sediment Level

RIGHT

WRONG

Heavy Tank Walls may be drilled and tapped - if thickness is sufficient to engage 3/4 of
threads.

Lighter Tank Walls must be equipped with suitable pipe coupling attached with proper
solder or weld material.

Care must be taken to insure the heated portion does not extend into the coupling area.

Approx. Cold End
(See Warning)

Figure 2 - Exploded View Screw Plug Mounting

2”

Locate Drain Pipe at Bottom of Heater,

Sediment Deposits may be

Removed Through Drain Pipe

Maximum Sediment Level.

Install Heater Above

This Level But As

Near to it as Possible for Maximum

Heated Liquid Storage Capacity

Suitable

Wiring

Drip Loop Recommended

to Minimize Passage of Moisture

Along Wiring Into Terminal

Wiring and Connections

Outlet

Inlet

Figure 4 - Closed Tank in Vertical Position

2

Heater

Outlet

Inlet

Note: In A Forced Circulation System,

Use Pump On Inlet Side.

Figure 3 - Closed Tank in Horizontal Position