Multiaqua CFFWA Series, Operating Manual

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Concentrations of Propylene Glycol in excess of 50% will destroy o-rings in fittings and pump. Water should
be added to the system first or a liquid solution diluted Propylene Glycol mix.
Before filling system with Propylene Glycol and water, pressure test the piping system with compressed air.
Testing should be done at a minimum of 50 psi but no greater than 50 psi over the system's normal operating
pressure. The system should hold air pressure for a minimum of one hour with no leakage.
System that contains 50 or more U.S. gallons should have a tee fitting with a stopcock installed in the return
line close to the chiller. The stopcock can be opened and attached to a hose with a female X female hose
fitting. In the open end of the hose section (1 -1.5 feet long) insert a funnel and pour into the system the
diluted Propylene Glycol/liquid solution mixture or add water first and then the quantity of Propylene Glycol
needed for minimum ambient protection (refer to Table 6). After adding the Propylene Glycol /water mixture, or
liquid solution and then coolant proceed to add enough water to the system to achieve a 15 psi gauge pressure.
To measure system pressure shut off the stopcock, remove hose and attach a water pressure gauge. Open
the stopcock to read system pressure.
Systems that use the Chilled Liquid Solution Storage Tank should be filled at the tee/stopcock fitting in the
outlet fitting of the storage tank. Fill the tanks with 10 gallons of water and with a funnel pour the calculated
(refer to Table 6) amount of Propylene Glycol into the tank. The amount of Propylene Glycol added should be
calculated to achieve minimum ambient protection. After adding Propylene Glycol, fill the system with enough
liquid solution to bring system pressure to approximately 15 psi gauge pressure. To measure system pressure
shut off the stopcock and attach a water pressure gauge. Open the stopcock to read system pressure.
Since we have the system filled we must eliminate the air left in the system. Briefly open each bleed valve at
the air handlers and allow trapped air to escape. This will eliminate much of the air left in the system.
Next we will start the pump and continue bleeding air from the system. Be sure the chiller has line voltage
available to it and set the chilled liquid solution control up to 100°F, which will ensure that only the pump runs
at this point. The pump should now start and remain running. Should the pump stop at any time during this
process it is an indication that the flow switch had air move across it allowing the circuit to be interrupted.
Continue to bleed some air out of the system at the highest locations before resetting the pump bypass timer
to get the pump running again. Open and close the power supply switch to the chiller to restart the pump.
Continue bleeding air with the pump operating. You may have to start and re-start the pump a few times to
complete air removal.
All piping systems should have a minimum of 10% Propylene Glycol in the system even in climates with non-
freezing ambient temperatures.
Using less than the recommended Propylene Glycol percentage content voids equipment warranty.
Liquid solution control valves (solenoid or motorized valves) should be selected for low pressure drop. If a selected
valve contributes to pushing your total head calculation to more than 50 feet of head, a larger valve may be
needed to bring your total head below the maximum of 50 feet.
Liquid solution balancing will require an accurate digital thermometer to measure return line liquid solution
temperature at each air handler. Set the chilled liquid solution temperature control in the chiller at a normal
operational temperature (44°F) and measure pump discharge temperature with the digital thermometer to check
system solution temperature. After the chilled liquid solution temperature has lowered to the set point begin the
balancing process. The system must be free of air and each air handler set at a temperature low enough to
continue cooling operation (and liquid solution flow) during the balancing process. Begin by measuring the return
line chilled liquid solution temperature of each air handler. Begin incrementally closing the supply line balance
valve at the air handlers with the lowest return line chilled liquid solution temperature. Continue this process
until each air handler has close to the same return line chilled liquid solution temperature.
73
Filling System with Liquid Solution and Coolant
Air Elimination
(Propylene Glycol)
Liquid Solution Balancing: