Daikin Rooftop System MPS 020G

The Maverick II includes the following refrigerant sensors or switches.

1. Low refrigerant pressure sensing, operating switch, automatic reset.

a. Disables associated compressors on a drop in suction pressure to approximately 35 psig.

b. Enables associated compressors on a rise in suction pressure to approximately 60 psig.

2. High refrigerant pressure, protective switch, manual reset at keypad.

The low pressure switch senses refrigerant pressure through shrader fittings that contain cores. The cores are stop valves that do not allow refrigerant to flow through the Shrader unless the device is in place. Therefore, the low pressure switch can be replaced without reclaiming the refrigerant.

The Shrader that serves the high pressure switch does not contain a core in order to maximize the functionality of the safety. Therefore it cannot be replaced unless the refrigerant has already been reclaimed.

The need for periodic cleaning of the energy recovery wheel will be a function of operating schedule, climate and contaminants in the indoor air being exhausted and the outdoor air being supplied to the building.

The Daikin wheel is “self-cleaning” with respect tiny particles due to its laminar flow characteristics. Smaller particles pass through; larger particles land on the surface and are blown clear as the flow direction is reversed. Any material that builds up on the face of the wheel can be removed with a brush or vacuum.

The primary need for cleaning is to remove oil based aerosols that have condensed on energy transfer surfaces.

A characteristic of all dry desiccants, such films can close off micron sized pores at the surface of the desiccant material, reducing the efficiency by which the desiccant can adsorb and desorbs moisture and also build up so as to reduce airflow.

In a reasonably clean indoor environment such as school or office building, measurable reductions of airflow or loss of sensible (temperature) effectiveness may not occur for several years. Measurable changes in latent energy (water vapor) transfer can occur in shorter periods of time in applications such as moderate occupant smoking or cooking facilities.

In applications experiencing unusually high levels of occupant smoking or oil based aerosols such as industrial applications involving the ventilation of machine shop areas for example, annual washing of energy transfer may be necessary to maintain latent transfer efficiency.

Proper cleaning of the energy recovery wheel will restore latent effectiveness to near original performance.

To clean, gain access to the energy recovery wheel and remove segments. Brush foreign material from the face of the wheel. Wash the segments or small wheels in a 5% solution of non-acid based coil cleaner (such as Acti-Klean, available through Daikin, Stock # AK1) or alkaline detergent and warm water. Soak in the solution until grease and tar deposits are loosened

(Note: some staining of the desiccant may remain and is not harmful to performance).

Obtain access to the pulley side bearing access plate

Loosen the screw in the bearing lock collar using a hexagonal wrench

Tap collar in the direction of wheel rotation to unlock collar using a light hammer and drift

Remove two nuts which secure bearing housing to the bearing support beam using a socket wrench with extension

Remove the diameter seal retaining screws using a wrench

Remove diameter seals from bearing beam

Routine Quarterly Cleaning of Option E Coated Coil Surfaces

Quarterly cleaning is essential to extend the life of an Option E Coated Coil and is required to maintain warranty coverage.

Coil cleaning shall be part of the unit’s regularly scheduled maintenance procedures. Failure to clean an Option E Coated Coil will void the warranty and may result in reduced efficiency and durability in the environment.

For routine quarterly cleaning, first clean the coil with the below approved coil cleaner. After cleaning the coils with the approved cleaning agent, use the approved chloride remover (under the Recommended Chloride Remover section) to remove soluble salts and revitalize the unit.

Coil cleaned with approved cleaner?

Chloride removed with recommended remover?

Supply fan motors should have grease added after every 2000 hours of operation.

Motor is warm, but not running?

Upper and lower grease plugs removed and cleaned?

Grease fitting inserted into the upper hole and a small amount of clean grease added with a low pressure gun?

Motor run for five minutes before installing the upper grease plug?

Sign off on the supply fans bearings lubrication