lev-co 13-12, Руководство пользователя

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4 Type 2
4.1 Mechanical Installation
A type 2 control package comprises two units: a control cabinet that also includes a MANUAL / OFF /
AUTO switch, a FAN ON indicator, a pressure gauge and transmitter, and a separate VFD. The control
panel may include a fused disconnect or this may be supplied externally by others. The elements may
be mounted as desired, although care must be observed in selecting the location of the VFD.
The VFD must be located within a 50m cable run from the motor for best performance and motor life.
See section 3 of the Invertek Optidrive ECO User Guide (or the appropriate sections for the other drive
types) for detailed VFD installation information. Note that the VFD keypad is used for setup functions
and should thus be easily operator-accessible. Note also that it is preferable to have the control cabinet
and the VFD in reasonably close proximity to minimize noise pickup on the shielded wiring carrying the
4-20mA control signal.
A tubing connection is required between the control panel and the main duct for pressure sensing. This
connection is made with clear PVC tubing of 3/16” ID, supplied in the installation kit. Drill an 11/32” di-
ameter hole in the main duct downstream from the fan but ahead of the first damper. Tap with a 1/8-
27NPT tap such as Acklands-Grainger part number WSWPT18. Screw in a 3/16” hose barb as supplied
by Lev-co in the installation kit – ensure it is tight. Run the tubing back to the control cabinet, through
the strain relief grommet in the base, and up to the tee connector which splits the sense line to the
pressure sensor and the indicator.
Connect to the minus or low inputs of the pressure sensor (IM-
PORTANT!) and the indicator.
Figure 9 - Pressure Sensor