Specifications

8. No point in the drain system may be above the drain connection of any unit.
9. Automatic flow controlled devices must not be installed prior to system cleaning and flushing.
10. A high point of the piping system must be vented.
11. Check local code for the need for dielectric
Flexible Hose
Since hose may change in length from +2% to –4%
under the surge of high pressure, it is necessary to provide
sufficient slack for expansion contraction (see Figure F).
Cleaning and Flushing System
1. Prior to first operation of any conditioner, the water circulating system must be cleaned and flushed of
all construction dirt and debris.
If the conditioners are equipped with water shut off valves, either electric or pressure operated, the
supply and return run outs must be connected together at each conditioner location. This will prevent
the introduction of dirt into the unit. Additionally, pressure operated valves only open when the
compressor is operation.
1 1/ 2"
( 38mm)
( 20mm PER METER)
1/ 4" PER FOOT
(38mm)
1 1/ 2"
F I GURE E
WRONG
RI GHT
FI GURE F
2. The system should be filled at the city water makeup connection with all air vents open. After filling,
vents should be closed.
The contractor should start main circulator with pressure reducing valve makeup open. Vents should be
checked in sequence to bleed off any trapped air to assure circulation through all components of the
system.
Power to the heat rejecter unit should be off, and the supplementary heat control set at 80°F (27℃).
While circulating water, the contractor should check and repair any leaks in the piping. Drain at the
lowest point(s) in the system should be opened for initial flush and blow-down, making sure city water
fill are set to make up water at the same rate. Check the pressure gauge at pump suction and manually
adjust the makeup to hold the same positive steady pressure both before and after opening the drain
valves. Flush should continue for at least two hours, or longer if required, to see clear, clean drain
water.
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