Water Treatment; System Pressurization; Filling The System - Carrier AQUASNAP 30RB060-390 Installation Instructions Manual

WATER TREATMENT Fill the fluid loop with ,a_ater(or
brine) and a COlTOsion-resistant i nhibitor suitable for the water
of the area. Consult the local water treatment specialist for
characteristics of system water and a recolrnnended inhibitor
for the cooler tluid loop.
SYSTEM PRESSURIZATION A proper initial cold till
pressure must be established before filling of the unit. The
initial cold *ill pressure is the pressure applied at the tilling
point to till a system to its highest point, plus a minimum
pressure at the top of the system (4 psig minimum [27.6 kPa])
to operate air vents and positively pressurize the system. The
expansion tank is very important to system pressurization. The
expansion tmlk serves several purposes:
1. Provide NPSH (Net Positive Suction Head) required for
the pump to operate satisfactorily.
2. Set system pressure.
3. Accolrnnodate expansion/contraction of water due to
temperature changes.
4. Acts as a pressure reference for the pump.
The expansion tmlk pressure must be set BEFORE the
system is tilled. Follow the manufacturer's recommendation
for instructions on setting the pressure in the expansion tank.
NPSHR intbnnation is provided on the Pump Culaes in
Fig. 28-35 tbr units with factory-installed hydronic kits. See
Table 6 tbr pump impeller sizes.
Once the system is pressurized, the pressure at the connec-
tion point of the expansion tank to water piping will not change
unless the water loop volume changes (either due to addition/
subtraction of ,a_ater or temperature expansion/contraction).
The pressure at this point remains the same regardless of
whether or not the pump is running.
Since the expansion tank acts as a reference point for the
pump, there cannot be two re*}rence points (two expansion
tanks) in a system, unless manifolded together. Where two or
more 30RB chillers with the hydronic option are installed in
parallel, there should not be more than one expansion tank in
the system, unless mani*blded together as seen in Fig. 25. It is
permissible to install the expansion tank(s) in a portion of the
return water line that is common to all pumps, providing that
the tank is properly sized for combined system volume.
If the application involves two or more chillers in a primary
secondary system, a common place for mounting the expan-
sion tank is in the chilled ,a_ater return line, just before the
&coupler. See Fig. 25 tbr placement of expansion tmlk in
primary-secondary systems.
If a diaphramn expansion tank is utilized (a flexible
diaphiamn physically separates the water/air interface) it is not
recolrnnended to have any air in the water loop. See the section
on air separation on page 28 for instructions on providing air
separation equipment.
FILLING THE SYSTEM The initial fill of the chilled
water system must accomplish three goals:
1. The entire piping system must be tilled with water.
2. The pressure at the top of the system must be high enough
to vent air fiom the system (usually 4 psig [27.6 kPa] is
adequate for most vents).
3. The pressure at all points in the system must be high
enough to prevent flashing in the piping or cavitation in
the pump.
The pressure created by an operating pump affects system
pressure at all points except one the connection of the
expansion tank to the system. This is the only location in the
system where pump operation will not give erroneous pressure
indications during the tilt. Therefore, the best location to install
the till connection is close to the expansion tank. An air vent
should be installed close by to help eliminate air that enters
during the till procedure.
When filling the system, ensure the tbllmving:
1. Remove temporary bypass piping and cleaning/flushing
equipment.
2. Check to make sure all drain plugs are installed.
Normally, a closed system needs to be filled only once. The
actual filling process is a thirly simple procedure. All air should
be puNed or vented tiom the system. Thorough venting at high
points and circulation at room temperature for several hours is
highly recommeMed.
NOTE: Local codes concerning backflow devices and other
protection of the city water system should be consulted and
followed to prevent contamination of the public water supply.
This is critical when anti-fieeze is used in the system.
Table 6 -- Pump Impeller Sizes
UNIT PUMP SINGLE PUMP
30RB Hp Option Code * Rpm Impeller Dia.(in.)
3 0 1750 6.5
5 1 1750 7.3
060
070 7.5 2 1750 8.15
10 3 3450 5.4
5 1 1750 7.3
080 7.5 2 1750 8.15
090
100 10 3 3450 5.4
15 4 3450 6.1
5 1 1750 7.3
110 7.5 2 1750 8.15
120
130 10 3 3450 5.4
15 4 3450 6.1
5 1 1750 6.5
150
160 7.5 2 3450 4.6
170 10 3 3450 5.0
190
15 4 3450 5.5
Pump Curve
I
I
I
II
I
I
II
II
I
I
II
II
Ill
IV
IV
IV
DUAL PUMP
Option Code* Rpm Impeller Dia.(in.)
6 1750 6.5
7 1750 7.3
8 1750 8.15
9 3450 5.25
B 3450 5.9
7 1750 7.3
8 1750 8.15
B 3450 5.4
C 3450 8.1
7 1750 7.3
8 1750 8.15
B 3450 5.4
C 3450 8.1
8 3450 4.6
B 3450 5.0
C 3450 5.5
Pump Curve
V
V
V
Vl
Vl
V
V
VII
VII
V
V
VII
VII
VIII
VIII
VIII
*Option Code refers to the Hydronics Option (position 11) in the model number. See Fig. 1 for
option identification.
NOTE: Pump Selections are chiller size dependent. For example, dual pump "C" on a 3ORB170
chiller is not the same as dual pump "C" on a 30RB130 chiller.
33