®
Chromalox
SERVICE REFERENCE
Installation, Operation
DIVISION
SALES
4
SECTION MTO-LT
(Supersedes PD441)
and
REFERENCE
PD441-1
MAINTENANCE INSTRUCTIONS
161-303567-001
DATE
MARCH, 1999
Type MTO-LT
Pipe Insert Immersion Heater
A
Expansion Gap
B
2-3/8”
Max.
Spacer
2-1/16”
I.D. Min.
Type E2
Moisture-Tight
Explosion-Resistant
Enclosure
Pipe, Support &
Tank (by others)
Expansion Gap
3/4” Pipe Outlet
GENERAL
Dim. (In.)
A
Pipe
Thd.
the ultimate choice of pipe material based upon his knowledge of the
chemical composition of the corrosive solution, character of the material
entering the solution and controls which he maintains on the process.
Chromalox cannot warrant any electric immersion heater against failure,
if such failure is the result of corrosion due to improper material selec-
tion by the user.
Model
kW
Volts
Phase
B
MTO-241LT
MTO-241LT
MTO-251LT
MTO-251LT
MTO-275LT
MTO-275LT
MTO-212LT
MTO-213LT
4
4
5
240
480
240
480
240
480
480
480
1
1
1
1
1
1
1
1
127
127
163
163
211
211
319
367
120
120
156
156
204
204
312
360
2
2
2
2
2
2
2
2
5
7.5
7.5
11.5
13
1. Heater Construction Characteristics:
A. High quality resistance wire held in place by compacted
Magnesium Oxide Refractory enclosed in an Incoloy® sheath.
B. Low to High Watt densities.
C. Explosion Resistant/Liquid-Tight E-2 terminal enclosures
are standard.
WARNING: Calculate and allow for thermal expansion.
Pipe insert will expand upon heating. The rear end of the
pipe insert must remain free from the tank wall. Heating
elements will also expand upon heating and must not
extend to the end of the pipe insert.
Chromalox type MTO-LT screwplug immersion heater is designed
for insertion into a 2” or larger pipe.
WARNING: It is the responsibility of the purchaser of the heater to make
WARNING: Users should install adequate 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 the
installation is the responsibility of the user, Chromalox
will assist in identifying equipment options.
INSTALLATION
WARNING: Hazard of Shock. Disconnect all power
before installing heater.
This Portion of Heater Above Liquid Level and
Exposed to Air Will Lead to Premature Burnout of Element
Expected Low
Level of Liquid
1. Before installing, check your type MTO-LT pipe insert heater
for any damage that may have occurred during shipment.
2. Check to insure that the line voltage is the same as that stamped
on the nameplate.
3. Do not bend the heating elements. If bending is necessary,
WRONG
consult factory.
RIGHT
Expected Maximum
4. IMPORTANT: Mount heater in the tank so that the liquid level
will always be above the effective heated portion of the heater (see
Figure 1). If the heater is not properly submerged, it may overheat
and damage the heating elements and create a possible fire hazard
due to excessive sheath temperatures.
Sediment Level
Note: Locate Heater as low as possible for maximum liquid storage capacity. Heat
does not move downward.
5. Where work will pass over or near equipment, additional protec-
tion such as a metal guard may be needed.
Figure 1 - Open Tank Installation
© 2010 Chromalox, Inc.
OPERATION
1. Do not operate heaters at voltages in excess of that stamped on the
ject to a humid environment. This moisture absorption results in a
cold insulation resistance of less than twenty megohms. Normally,
this megohm value corrects itself after heatup and does not affect
heater efficiency or life.
heater since excess voltage will shorten heater life.
2. Always maintain a minimum of 2” of liquid above the heater to
prevent exposure of the effective heated length. If the heater is not
properly submerged, it may overheat and shorten heater life. DO
NOT OPERATE HEATER IF TANK IS DRY.
A low megohm condition can easily be corrected by removing the
terminal hardware and terminal enclosure and baking the heater in
an oven at 350˚F for several hours, preferably overnight. Note:
The lid must be removed from the housing.
3. Be sure all trapped air is removed from a closed tank. Bleed the air
out of the liquid piping system and heater housing prior to ener-
gizing.
Note: The tank or heating chamber in closed tank systems
must be kept filled with liquid at all times.
An alternate procedure is to energize the heaters at low voltage
until the megohm reading returns to normal. When energizing
heaters in air, the sheath temperature should not exceed 750˚F.
4. Keep heating elements above sediment deposits.
5. Low Megohm Condition — The refractory materials used in
electric heaters may absorb moisture during transit or when sub-
MAINTENANCE
3. Remove any accumulated sludge deposits from around pipe
and from tank.
WARNING: Hazard of Shock. Disconnect all power to
heater before servicing or replacing heaters.
4. Check for loose terminal connections and tighten if necessary.
5. If corrosion is indicated in the terminal housing, check terminal
box gasket and replace if necessary. Check conduit layout to cor-
rect conditions that allow corrosion to enter the terminal housing.
6. Clean terminal ends of all contamination.
1. Heaters should be checked periodically for coatings and corrosion
and cleaned if necessary.
2. The tank should be checked regularly for sediment around the
heater pipe insert as sediment can act as an insulator and shorten
heater life.
Limited Warranty:
Please refer to the Chromalox limited warranty applicable to this product at
2150 N. RULON WHITE BLVD., OGDEN, UT 84404
Phone: 1-800-368-2493
TA - Q0 - EF
Litho in U.S.A.
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