8.Refill the system with clean, chemically treated water. Since water varies for each locality, contact a local water treatment company for the correct treatment chemicals to use in the area. Set the boiler to raise the loop temperature to approximately 85 F.
.
CAUTION
To avoid possible damage to piping systems constructed of plastic piping DO NOT allow loop temperature to exceed 110 F.
Circulate the solution for a minimum of 8 to 24 hours. At the end of this period, shut off the circulating pump and drain the solution. Repeat system cleaning as necessary.
9.When the cleaning process is complete, remove the short- circuited hoses. Connect the hoses to the proper supply and return connections on each unit. Refill the system and bleed off all air.
10.Test the system pH with litmus paper. The system water should be slightly alkaline (pH 7.0 to 8.5). Add chemi- cals, as appropriate, to maintain acidity levels.
CAUTION
DO NOT use
11.When the system is successfully cleaned, flushed, refilled and bled, check the main system panels, safety cutouts and alarms. Set the controls to properly maintain loop temperatures.
System Checkout — When the installation is complete and the system is cleaned and flushed, follow the system checkout procedure outlined below.
1.Voltage: Ensure voltage is within the utilization range specifications of the unit compressor and fan motor.
2.System Water Temperature: Ensure temperature is within an acceptable range shown in Table 8. (When conducting this check, also verify proper heating and cooling set points.)
Table 8 — Air and Water Limits
50PEC UNIT | COOLING (F) | HEATING (F) |
Min Ambient Air | 50 | 50 |
Rated Ambient Air | 80 | 70 |
Max Ambient Air | 100 | 85 |
Min Entering Air | 50 | 50 |
Rated Entering Air, dry bulb/wet bulb | 80/67 | 70 |
Max Entering Air, dry bulb/wet bulb | 100/83 | 80 |
Min Entering Water | 30 | 20 |
Normal Entering Water | 85 | 70 |
Max Entering Water | 110 | 90 |
NOTES:
1.Minimum air and water conditions can only be used at nominal flow rates.
2.50PEC units may have up to two values at maximum or minimum with all other parameters at normal conditions.
3.Operating limits shown are for
3.System Water pH: Verify system water is slightly alkaline (pH = 7.5 to 8.5). Proper pH promotes the longevity of the hoses and heat exchangers. See Table 9.
4.
5.Balanced Water Flow Rate to Heat Pump: Record the inlet and outlet water temperatures as each heat pump unit is started. This check will eliminate nuisance unit tripouts resulting from water velocities that are either too low or too high; it can also prevent erosive water flow rates.
6.Standby Pump: Verify the standby pump is properly in- stalled and in operating condition.
7.System Control: To ensure no catastrophic system fail- ures occur, verify system controls are functioning and the sequencing is correct.
8.Freeze Protection for Water Systems: Verify freeze protection is provided for the outdoor portion of the loop water system. Inadequate freeze protection leads to expensive repairs.
CAUTION
To avoid equipment damage, DO NOT leave system filled in a building without heat during the winter unless anti- freeze is added to system water. Condenser coils never fully drain by themselves and will freeze unless winterized with antifreeze.
9.System Water Loop: Verify all air is bled from the sys- tem. Air in the system impedes unit operation and causes corrosion in the system piping.
10.Unit Filters: To avoid system damage and to provide maximum performance, ensure the unit filter is clean.
11.Unit Fans: Manually rotate fans to assure free rotation. Ensure fans are properly secured to the fan shaft. Do not oil fan motors on
12.System Control Center: To ensure control of the tempera- ture set points for operation of the system’s heat rejector and boiler, examine the system control and alarm panel for proper installation and operation.
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