Emerson LTM-300 manual Installation and Wiring Strap-On Transmitter Installation

3. Level/Interface. A second float may be added below the first one, and the second output will be calibrated automatically. The second time interval is measured in the same manner as the first and added to the first to derive the position of the heavier float.

The same six inch dead zone applies to the measurement of the second level although the reasons are different. This will typically correspond to a physical separation of the two floats by approximately three inches. The float size, geometry, magnetic strength all play a factor in how close the two floats can get without interfering with each other.

SECTION 3. Installation and Wiring

3.0 Strap-On Transmitter Installation

CAUTION:

During installation, do not attempt to twist or turn the head of the transmitter. Damage to the detector assembly may occur if the head is rotated . If the head is loose, please notify the factory.

The LTM-300 can be mounted to the side of a MagTech LG series level gage using a special mounting bracket and stainless steel hose clamps. When mounting the transmitter to an LG series gage the active sensor region of the probe should fall within the centerline of the process connections on the gage. If the transmitter deadband region is inside the centerline of the process connections the transmitter will not output an accurate measurement because the active region of the probe is too short. When placing an order for a transmitter to accompany an existing gage it is important to indicate the style of the gage, the temperature and the center-to-center dimensions. Calibration of the probe will be factory set along the active region of the probe; however, a field calibration may have to be performed to match the probe to the desired control room specifications.

If a transmitter is being purchased for an interface gage, the calibration for the probe should be done in the field to ensure a proper control room

reading. For long transmitters it may be desirable for the operator to have the electronics housing mounted at the bottom of the gage for easy access.

THIS MUST BE SPECIFIED AT TIME OF PURCHASE.

Installation Note (European):

The cable entry devices and blanking elements of unused apertures shall be of a certified flameproof type, suitable for the conditions of use and correctly installed.

3.1 Standalone Transmitter Installation

The LTM-300 stand-alone transmitter comes equipped with a 3/4” compression fitting, mounted approximately 6.00” below the electronics housing. The fitting is placed in this area to ensure the transmitter is calibrated in the sensor tubes active region. Refer to the stand-alone drawings for a visual description of the transmitter features. Optional mounting configurations are available upon request.

The magnetic float used in the stand-alone unit is designed to travel up the sensor tube with the change in fluid level. If build-up of process or contaminates should restrict the movement of the float, the transmitter sensor tube will have to be cleaned or the float may have to be replaced with one that has a wider inside diameter. The floats are designed to match the pressure and specific gravity for the process being measured and come in various materials ranging from stainless steel to kynar.

The magnetic float can be changed out at any time to accommo- date the processes being measured. The float stop, located at the bottom of the transmitter, can be removed to allow the float to slide off the sensor tube.

PLEASE NOTE:

If using a transmitter configured for dual level output or interface measurements, remember to slide the float with the lightest grav- ity range first.

INTERCONNECT WIRING (CSA & FM)

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