Armstrong Multi-Point and Retrofit Purger with "Loss" Calculator

28 Pages·2013·1.53 MB·English

Armstrong Multi-Point and Retrofi t
Purger with "Loss" Calculator
Installation and Operation Manual
Model XR1502 Series (Multi-Point Purger)
and 370XR Series (Retrofi t Purger)
Installation and Set Up Overview
Warning:
These installation, operation and technical
instructions should be used by experienced
personnel as a guide to insure that the Armstrong
XR1502 Series (Multi-Point Purger) and 370XR
Series (Retrofit Purger) function in a correct
manner. Selection or installation of equipment
should always be accompanied by competent
technical assistance. We encourage you to contact
your local representative or the Armstrong Factory
if further information is required.
Installation Instructions 1
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Connecting the Purger to the Refrigerated System 2
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Piping Tips 4
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Purge Connections for Condensers 4
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Purge Connections for Receiver 4
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Installation Notes 5
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Installation Procedure for 370XR Retrofi t Purger 7
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Operation 8-10
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Start Up Procedures 11-13
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Trouble Shooting 14
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Field Wiring Diagrams 15-18
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Addendum 1: Accessing the Ethernet Data 19-24
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Limited Warranty and Remedy 25
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Installation
XR1502 Series Multi-Point Purger and 370XR Series Retrofi t Purger
Warning:
All installation and service performed on the
Armstrong Purger should be performed by
competent personnel. Observe all safety
precautions plus wear protective clothing and eye
protection at all times.
Location of Purger: The purger should be installed in a dry Gauge Glass: The gauge valves, glass and glass guard
location, convenient for operation and inspection, usually in supplied with the XR1502 Series Purger are packed
the compressor room. Where practical, install at a higher separately and should be installed after the purger is in the
elevation than the liquid receiver. line.
Note: Multi-Point Purgers do not include a gauge glass.
Mounting the Purger: The purger should be fastened
securely to a wall or column. Two ½” tapped holes are
provided in the purger housing to facilitate mounting
(see Fig. 1-1).
Fig. 1-1
Page 1
Installation Procedure
Connecting the Purger to the Refrigeration System
The Liquid Supply for the purger must come from a point Suction Connections: Piping should be at least ¾” pipe.
where liquid refrigerant is always available, possibly the Connect to main suction line at any convenient point where
receiver. low pressure is always present.
Note: Be certain the liquid supply comes from the same Note: For best operation always connect the purger to the
pressure source as the purge points. closest possible suction
Connect the Purger to the Electrical Supply: Any Purge Point Connections: Purge point connections
properly grounded 120/240 VAC. 50/60 HZ 15 AMP supply should be ½” minimum. Location of these connections is
will be sufficient. Refer to Fig. 13-1, the Field Wiring discussed in more detail on Page 3.
Diagram for XR1502 Series & 370XR Series Multi-Point
Purgers. Surge suppression is also recommended. Operation Solenoid: A, B & C as well as needle valves D
& E are supplied with the purger. Purge point solenoids
G & H are accessory items (see Fig. 2-1). All operational
solenoid valves are normally closed valves.
Fig. 2-1, How an Armstrong XR1502 Series Multi-Point Purger fits into a refrigeration system
OIL SEPARATOR
ARMSTRONG
OIL DRAIN
TRAP
D
CONDENSER
B
COMPRESSOR
C
E G
Expansion
Valve MP H
Purger Purge Point
Valve
(optional)
A K-3
Electronic
Purger
Armstrong Bubbler Controller
Strainer (optional)
Armstrong
Liquid
Seal
Armstrong
Strainer
EVAPORATOR NOTE: A, B & C = Solenoid Valves Included
D & E = Metering Valves Included
RECEIVER
Page 2
Installation Procedure (continued)
Connecting the Purger to the Refrigeration System
Purge Point Solenoids should be mounted as close to the Purge Piping for Centrifugal Machines: A purge “saddle”
condenser coil and receiver purge connections as practical. is usually provided on top of the condenser as shown in
A strainer with .045 perforated or finer screen material Fig. 3-3. The three purge outlets are connected and a
should be installed ahead of the purge solenoid valves. single purge line run to the purger.
NOTE: If you suspect more than 5 psi differential pressure
Purge Piping for Multiple Condensers: Provide a separate between purge points, a check valve should be used on the
purge connection from each condenser and from each coil low pressure purge points.
of evaporative condensers. Since only one purge point is
Fig. 3-3
purged at a time, piping can be saved if the purge points
are piped into a single manifold and then run to the purger
as shown in Fig. 3-1 and Fig. 3-2.
Fig. 3-1
CONDENSERS
Conventional purge saddle and pyrometer readings of surface
temperatures.
XR1500
PURGER
RECEIVER
Purge lines and valves manifolded together.
Fig. 3-2
EQUALIZING LINE
CONDENSERS
XR1500
PURGER
RECEIVER
Purge lines for an evaporative condenser in parallel with a shell and
tube condenser.
Page 3
Installation Procedure (continued)
Piping Tips
Purge Connections for Condensers Horizontal Shell and Tube Condensers: Fig. 4-3.
Incoming gas carries air molecules to the far end of the
Evaporative Condensers: In these drawings, long arrows condenser near the cooling water inlet as shown. Purge
show high gas velocity. Arrow lengths decrease as gas from point "X". If purge connection is at "Y", no air
velocity decreases approaching the no-velocity zone. Air will reach the connection against the gas flow until the
accumulation is shown by black dots. condenser is more than half full of air.
Fig. 4-1. High velocity of the refrigerant gas entering Fig. 4-3
the condenser is caused by the volume change when
condensing occurs. This high velocity carries any non-
condensables and air to the discharge or liquid outlet end
of the coil. This is where the purge point "X" should be
located.
Note: Do not try to purge from the coil inlet "Y".
Fig. 4-1
Fig. 4-4. Incoming refrigerant blows air to each end of the
condenser. Air at the left hand end can’t flow against the
incoming gas to escape through the right hand connection
at "X". Provide a purge connection at each end. However,
1
if the condenser is equipped with a purge “saddle” (as in
Fig. 3-3) only one purge point is used.
Fig. 4-4
Vertical Shell and Tube Condensers: Fig. 4-2. Low
gas velocity will exist at both the top and bottom of the
condenser. Purge connections are desirable at both "X"
1
and "X".
22
Fig. 44--22
Purge Connections for Receivers
Fig. 4-5. Purge from point "X", farthest away from the
liquid inlet. The incoming liquid flow will push any air to
the opposite end of the receiver.
FFiigg.. 44--55
Page 4
Installation Procedure (continued)
Installation Notes
Adherence to the following notes and recommendations High Liquid Head May Exceed K-3 Differential Valve
are very important in achieving a fully satisfactory, Capability: When the liquid refrigerant supply comes
trouble free installation. Please read them carefully. from more than 6 feet above the purger liquid outlet, a K-3
differential valve (a spring loaded check valve) may not be
able to maintain the liquid pressure at the purger outlet
below the inlet gas pressure. Under these conditions use
Differential Check Valve (K-3): With an expansion valve
a differential pressure regulator instead of a K-3 differential
between the purger liquid outlet and the refrigerating coil
valve (see Fig. 5-3).
inlet, pressures at the purge gas inlet and purger liquid
outlet are identical. Gas can not enter the purger because Fig. 5-3
a light spring holds the check valve in the bottom of the
purger closed, and there is no pressure differential to
permit gas to enter the purger (see Fig. 5-1).
RECEIVER
Fig. 5-1
TX
VALVE
XR1500
PURGER
DIFFERENTIAL
TX PRESSURE REGULATOR
VALVE
150 150
150 XR1500
PURGER
RECEIVER
150 Metering Valves (D & E): The supplied metering valves in
Fig. 2-1 are used to slow down the discharge rate from the
purger. The typical setting is 1/4 to 1/2 turns open.
Thermostatic Expansion Valve: Where high side or
A K-3 differential valve reduces the pressure at the purger
suction pressures vary, a thermostatic expansion valve is
liquid outlet to enable gas to enter the purger and liquid to
recommended. This valve may be installed with a by-pass
be discharged from the purger (see Fig. 5-2).
that includes a manually-controlled expansion valve. The
capillary bulb should be from 12” to 18” (31cm to 46cm)
away from the purger on the suction line.
Fig. 5-2
Thermostatic Expansion Valve Recommendations: With
suction temperature above 15°F, use a 2 ton valve. With
suction temperature below 15°F, use a 1 ton valve.
TX
VALVE
150 150 147 XR1500
PURGER
RECEIVER
K-3
150
Page 5
Installation Procedure (continued)
Installation Notes
Warning: Use pipe thread compound sparingly.
An excess may prevent the expansion valve from
operating.
Avoid Pockets in the foul gas line from the condenser to
the purger. They will form a liquid seal which will prevent
flow of gas to the purger.
Excessive Oil will interfere with purger operation. Remove
oil before you install your purger. Prevent further oil
accumulation by installing a separator in the discharge line
from compressor. This separator should be drained by
an Armstrong Oil Trap that discharges to the compressor
crank case through a suitable oil filter or to an oil barrel.
Oil Drain: Every purger is provided with a bottom oil drain.
Where oil accumulations are likely, install a ¼” Drain Valve
as shown in Fig. 6-1. To drain oil, pump down the purger.
When purger is at room temperature, open Oil Drain Valve
and crack a union on the purge line so oil can drain by
gravity.
Fig. 6-1
XR1500
Purger
Oil Drain Valve
Purge Outlet Check Valve: This check valve in the air
discharge line prevents siphoning liquid from the bubbler
back to the purger. This check valve is purchased as an
accessory item (K-1 check valve). The bubbler package
includes a check valve.
Page 6
Installation Procedure
Armstrong 370XR Series Retrofi t Purger
Disassemble the purger and existing piping. Remove the
existing cap, coil and float assembly and replace them
Warning: All installation and service performed on the
Armstrong Purger should be performed by competent with the new cap, coil, and float assembly. Remove the
personnel. Observe all safety precautions plus wear complete liquid discharge mechanism, bucket and scrub
protective clothing and eye protection at all times. wire assembly from the lower body. They are not required
for Multi-Point Purge operation. Reassemble the purger
Purger Shut-Down: (Fig. 7-1). Close valve "AA", "D", "B" body. Make the necessary piping changes to agree with
and "B". Under this condition, suction will be maintained Fig. 2-1 for adding solenoid valves "A", "B", "C" and metering
1
on the purger coil. As the purger warms up the expansion valves "D", "E".
valve will open. The liquid level inside the purger will drop. Note: Be certain the float switch assembly rod is pulled up
Leave the purger in this condition until all the frost is gone as high as possible, approximately 4 inches above the cap.
and the purger body is dry and warm. Then close valve "C" Do not move the fl oat stops!
(and "M"). Mount the electronic controller on a wall or other suitable
structure near the purger. Be certain the controller is
located in a visible non-obstructed and dry location.
Purge Point Valves should be installed for each purge
point. See pages 4, 5 and 6 for further details.
Wire the float switch, purge point valves and solenoid
Fig. 7-1 valves "A", "B", "C" to the PLC controller per the wiring
diagram (see Page 13).
Connect the PLC controller to the proper power source. Be
certain to follow proper state and local electrical code
requirements.
Liquid Seal Trap: Condensation of purge gas in long or
exposed lines will occur if the gas temperature exceeds the
temperature of the air surrounding the purge gas piping.
This condensation presents no problem if the amount is
less than the make-up liquid required to offset purger heat
gain. When the amount condensed exceeds make-up
requirements, a seal of liquid refrigerant will form ahead of
the purger as shown in Fig. 7-1.
When such a seal forms, gas cannot get to the purger.
Now the Tx valve has to supply only enough liquid to
keep the purger chilled and none for condensing gas so
the seal gets deeper and deeper. To cure this problem
the XR1502 Series Package Purger is equipped with an
Armstrong 1011-6 liquid seal trap (for ammonia service)
or an Armstrong 1011-12 (for freon service). The trap
discharges to the low pressure or suction side of the
system. This trap is a beneficial addition to any existing
system being retrofitted to automatic control.
Page 7
Operation
How the XR1502 Series & 370XR Series Multi-Point Purgers Operate
The XR1502 Series and 370XR Series purgers monitor Fig. 8-1
each purge point in the system for 5 minutes. This
ensures that all non-condensable gases have had a chance
to work their way from the purge point, through the piping,
to the purger.
When the temperature in the coil chamber reaches the
Temperature Setpoint and the float switch indicates a
pocket of gas has accumulated inside the purger body, the
purge solenoid valve "C" will open.
The purge solenoid valve "C" will close when the air
Fig. 8-2
has been discharged. Valve "C" will also close if the
temperature rises above the Temperature Setpoint or, if
the maximum purge time of 2 minutes has been reached.
Note: If the purge solenoid valve "C" has been energized
for more than 2 minutes, the unit will shut down and
energize the alarm.
If the liquid level in the purger body gets too low, both the
liquid feed solenoid valve "A" and the bypass solenoid valve
"B" will energize to refill the purger.
Note: Be sure the liquid supply is from the same pressure
source as the purge points. • Touch REFRIGERANT TYPE. Choose from 15 different
The purging Temperature Setpoint is field programmable. refrigerants - Ammonia, R-717 is the default.
It should be set at 5 to 10°F. above the compressor suction (see Fig. 8-3)
temperature, (i.e. compressor is at 8°F., Temperature Fig. 8-3
Setpoint to 13 to 18°F.)
Note: For the first few days on new installations, the
Temperature Setpoint should be set near the maximum
which is 45°F.
A water flush is provided for use with ammonia systems.
When the purge solenoid valve "C" is energized, a contact
closes to energize a water flush solenoid valve. The water
flush solenoid valve remains open for 30 seconds longer
than the purge solenoid valve "C" to flush the absorbed
purged gas from the bubbler.
• POINTS - This touch point goes to the pages where the
The electronic purger controller records and displays
system is told how many purge points are active or
days since last clear, total system purge time in seconds,
inactive (see Fig. 8-4). Highlighted squares are active.
total number of system purges, and refrigerant loss. This
information can be viewed on the controller touch screen Note: Anytime purge points are activated or de-
display. activated, return to SETUP on the MAIN menu, then
DISABLE SYSTEM and then ENABLE SYSTEM to refresh
changes.
Inputs
Fig. 8-4
• SETUP - Is the first input that should be touched
(see Fig. 8-1). In this input the system can be disabled/
enabled, the system alarms can be disabled/enabled, and
the system temperature setpoint can be changed. The
system temperature can also be changed to either °F or
°C. and the refrigerant being used can be selected. (see
Fig. 8-2).
Page 8