NorAire NC-FE series, Инструкция по установке и эксплуатации

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05/16/2014 9 NI216
Water Fill/Purge Procedure
Piping design and installation must include adequate shutoff valving and external connection valve/ports to
force pressure water around the system without any pockets or air voids within all plumbing loops. Careful
placement of these source and dump ports is very important with an in-between shutoff valve to make sure
exiting air does not get back into the system or remain trapped.
IDU heating and chilled supply out – both need to be purged independent and care must be taken so when
purging air does not re-enter the previous. Also, there is potential for trapped air within the internal defrost
bypass loop which can cavitate the internal pump.
Suggested purge and fill – to properly work through heating and chilled water supply outputs, with the defrost
bypass concern; it is mandatory that the installer perform proper purge and fill process. These next pages
provide a step by step procedure, following this is not necessary but it is provided as a guide. However, the
“purge or recheck defrost boiler bypass” section within this procedure is extremely important. This is over and
above what is normally required for a typical boiler/hydronic system. IDU power-on and the aquastat type
device (R to W or R to Y) should be active (installing technician could use an R to W or R to Y jumper).
Note:
After IDU power-on, must allow ACD timeout (power on LED is solid).
Basics
1. The pressure relief valve ( R ) is set at 30 psi. Verify there is an extension pipe bringing the output to a
bucket or floor drain. Typically city water and well water is higher than 30 psi. Thus you will either
need a regulator or a hand valve to manually make sure the hydronic circulating pressure is less than 30
psi so you do not “blow” the pressure relief. By throttling the introduced city water with a hand valve
you can control the pressure within the hydronics loop down.
2. Do not run a hydronic circulator dry or without water flowing. The motor can overheat in a very short
time and result in undesired troubleshooting conditions. A basic small hydronic circulator will not self
prime or pull water. There must either be a column of water (3 to 4 feet high) above the inlet of the
pump or a source pressure system which is initially forcing water through the pump. As little as a 1” to
3” air bubble within the inlet pipe can cavitate the pump and can stop circulation.
3. If there is a buffer tank, this should be totally filled before starting at the zone/loops. Remove the top
plug or cap and fill completely.
4. Typically there will be more than one radiant loop and probably more than one zone (zone typically
means several loops with a manifold collection). You must always start with one zone, then one loop,
and when all loops are individually purged, you move on to the next zone and repeat. When you feel
the previous zone is air purged, hand valve it closed, preferably on both sides of the manifold (A and B).
5. Determining when all the air is removed takes experience. Do not quit after it appears a set of bubbles
are gone and there is now a clear stream of water. Typically you need to drain long enough to where
there is a new circulation of water through the loop and system
after seeing the last bubble. If a typical
header piping and one 250-foot ½” loop holds 3.5 gallons and the city water is flowing at 2 GPM, you
should continue to see a steady stream of water for 3 minutes.
6. For purge and fill purposes, a forced air water coil circuit is treated basically the same as a zone, the
circuit must have its own input connection and drain connection with a valving method to force the city
water all the way around the circuit.
7. Almost any pressure water source could be used for purging, but at the end you should consider refilling
with a softened or mineral free water or rust inhibitor additives.
8. If your system needs antifreeze, first purge with a continuous water source and this procedure. If there
is a buffer tank, drain out (all valves around the tank closed) the water equal to the antifreeze you need
to add. Make sure the tank is totally filled (no air) before re-circulating system test and pressure
verification, reference the following steps 10 through 17.