Powered Rotary Ventilator (McVent)

Installation and Maintenance instructions.

McVent Power Driven Rotary ventilator.   (Post September 2004)

These fans operate on extra low voltage 12 or 24volt systems. It does not require a licensed person to carry out maintenance and repairs on these low voltage systems.

Description. The design of the unit is such that there is no fan blades in the air stream and the electric motor is remote from the air stream. The unit operates more like a centrifugal pump sucking the air up the vent tube and expelling it at the top.

The McVent unit has been designed to place a negative pressure on the system and remove any odour that may have been generated by the bacterial process from the system.   Strong excessive odour usually indicates a System digestive problem. See the relevant problem solving sections that discuss this in detail.

Installation instructions.

Notes.

This ventilator unit is designed to be installed on a 110mm DWV vent pipe or equivalent. It is possible to fit to a 150mm vent tube with the appropriate adaptor. Ideally the vent tube should be installed with the pipe being vertical for it's entire length. Deviations of 45 degrees in the vertical are acceptable however 90 degree bends will significantly reduce the airflow up the vent.

The unit comes supplied with 10m of cable already connected to the unit. This length of cable is designed to be dropped internally down the vent tube.

Install Procedure.

•  Cut the vent stack to length. Ideally it should finish approximately a minimum of 1m above the roof line.

•  Prior to installing the vent pipe drill an 8mm hole in the vent tube at around floor level of the building.

•  Install the coupling to the top of the vent pipe.

•  Install a draw wire inside the vent tube from the top and out the 8mm hole.

•  Install the vent pipe.

•  Install the ventilator first connecting the end of the cable to the draw wire.

•  Next drop the cable down the vent tube and draw the cable out the hole at the bottom.

•  Next fit the ventilator to the coupling.

•  Screw fix in place using the Stainless Steel fixings supplied.

•  Connect the cable to the power supply selected for your system.

•  Test run the unit.

•  Seal the cable penetration.

For trouble shooting guide see the section attached.

Maintenance.

Maintenance interval.

Procedure.

•  With a portable Multi-meter / amp meter check the current draw on the power delivery side of the switch mode power supply. See Photograph.   Current draw should be in the range of .208ma to .21ma in no wind conditions. The prevailing breeze will impact on the current draw lowering it relevant to the wind speed. Excessive current draw may indicate a problem.

•  On the Switch Mode power supply unit check to see the LED light is on. This indicates power to unit.

•  Perform a visual inspection of the ventilator. Look for balanced rotation and any build up of foreign material on the unit.

Trouble shooting guide.

•  Turn off power supply to the unit.

•  Visually from the ground with binoculars if available inspect the unit for build up of spiders webs or other.   This is unlikely but if it is excessive it may require removal.

•  Check for any visible surface corrosion. Again unlikely but if obvious it may require spraying with anti-corrosion type product.

•  If the unit has been hit by a branch it may have thrown the unit out of balance. It may require adjusting so that it runs in balance. Long term out of balance operation may reduce the unit's service life and draw more power to operate it.

•  If the current draw test shows excessive current draw and none of the above are obvious the unit may have an internal problem and it may require the unit to be brought to ground for checking.    

•  The unit will only rotate in one direction. It will spin by wind assistance but not operate electrically with polarity reversed. Check polarity on wiring if unit is stopping in no wind conditions.

•  If the unit is spinning freely and you have checked all the above but still stops in low wind conditions check that the power supply is turned on to it.

•  If the power supply is on check the power source is working. If the unit is Solar powered see the section on solar panels and batteries. If the unit powered by a 240/12 or 24volt transformer ensure that the unit is working. If not replace it.

At all times if you are required to access the ventilator be sure that you seek professional advice and follow all safety guidelines and requirements necessary when working at elevated heights.   

If and when you have checked the above and are still experiencing problems please contact your supplier or help on 1800 069 805.