McQuay MPC-HPC200 Installation Manual
Installation, Operation and Maintenance Manual
Group:
IM 856-1
Aftermarket Products
Field Installation Procedure
For PureCharge - Oil, Acid,
Moisture Removal Unit
©
2008 McQuay International
Part Number: IM 856-1
Date: January 2009
Supersedes: IM 856 dated April 2007
For Models:
MPC-LPC200-11/113
MPC-LPC200-123
MPC-HPC200
Table Of Contents
Hazardous Identification Information............................3
Installation......................................................................4
PureCharge Specifications .............................................4
Average refrigerant/oil mixture in tank per distillation..4
Contents of the PureCharge Installation Kit..................4
Field-Provided Items......................................................4
Preliminary Inspection ...................................................4
PureCharge Unit Operational Overview.........................5
How It Works.................................................................5
How the PureCharge Unit Transfers Oil to the Chiller’s
Oil Sump ........................................................................5
Operating Parameters.....................................................5
Operational LED Indicators ...........................................6
Diagnostic LED indicators.............................................6
Fault LED indicators......................................................6
Installing the PureCharge Unit.......................................8
Location and Mounting ..................................................8
Plumbing the PureCharge Unit.......................................8
Liquid Refrigerant Fill Line (with Strainer)...................9
Vapor Return Line..........................................................9
Oil Return Line and Oil Filter-Drier installation............9
Option 1 Oil Line Piping Instructions..........................11
Option 2 Oil Line Piping Instructions..........................11
Electrical Connection...................................................13
Power Requirement......................................................13
Optional Chiller Run Signal.........................................13
Connecting Power........................................................ 13
Initial Start-Up............................................................. 14
Start-Up Procedure ...................................................... 14
Description Of PureCharge Components..................... 15
Safety Features............................................................. 16
Electrical Control Box.................................................16
Logic Board Relays and Dip Switches ........................ 17
Switches (SW1) & (SW2) (Dip Switches)...................17
Maintenance................................................................. 21
EZ-Change Refrigerant Filter Drier Replacement
Instructions .................................................................. 21
Steps for Changing EZ Change Filter Drier................. 21
Periodic Maintenance .................................................. 22
Control Calibration...................................................... 22
Leak Testing Procedures.............................................. 22
PureCharge Evacuation Procedure .............................. 23
Troubleshooting........................................................... 24
Using Switch SW2 Dip Switches as a diagnostic aid.. 24
Troubleshooting Chart.................................................24
Switch light defective. ................................................. 24
Replace switch............................................................. 24
Troubleshooting the Liquid Level Sensor.................... 28
Liquid Level Sensor Replacement Instructions........... 28
Replacing Level Sensor Switch Electronic Module.....28
Procedure to Clear Oil Logged Distillation Tank ........ 29
2 IM 856-1
Introduction
The McQuay PureCharge unit is designed to remove oil,
acid & moisture from the refrigerant charge of a
centrifugal chiller and automatically return the oil to the
chiller’s oil sump. The PureCharge unit may be used with
centrifugal chillers using the following refrigerants: R-11.
R-113, R-114, R-123, R-12, R-22 and R-134a.
Hazardous Identification Information
! DANGER
Dangers indicate a hazardous situation which will
result in death or serious injury if not avoided.
! WARNING
Warnings indicate potentially hazardous situations
which can result in property damage, severe
personal injury, or death if not avoided.
! CAUTION
Cautions indicate potentially hazardous situations,
which can result in personal injury or equipment
damage if not avoided.
IM 856-1 3
Installation
! WARNING
Installing or servicing refrigerant support equipment
can be hazardous due to system pressures and
dangerous voltages. Only qualified service
personnel should work on such equipment.
PureCharge Specifications
Electrical power
requirements:
Remote alarm relay (rly)
contact rating
Operating environment: 70°F to 105°F, 5% to 80% relative
Storage environment: 0°F to 120°F, 5% to 80% relative
Dimensions
(approximate):
Weight (approximate): 60 pounds
Shipping weight
(approximate):
Operating distillation
temperature:
Operating pressures: 30 to 250 psi
Distillation tank factory
pressure tested at:
Average refrigerant/oil
mixture in tank per
distillation
(varies depending upon
installation and refrigerant
level in chiller):
Average rate of
refrigerant/oil mixture
processed (depends upon
installation, refrigerant
level in chiller, and
whether chiller is Running
or Off):
Note: The PureCharge unit comes
equipped with a remote alarm
capability.
Contents of the PureCharge Installation Kit
Each kit includes:
One Installation, Operation and Maintenance Manual.
One PureCharge unit with EZ-Change refrigerant
filter attached.
One oil filter/drier (for use in oil return line).
One liquid-line strainer (for use in refrigerant fill line).
120 VAC, 50/60 Hz., 1-Phase, 15amp fused circuit
Actual current draw approximately 4
Amps
120 VAC; 15 Amp
humidity, non condensing
humidity, non condensing
33" height x 16" length x 12" depth
95 pounds
155 F degrees
350 psig
10 to 20 lbs
850 to 1250 lbs. per week
44000 to 65000 lbs per year
One 1/4’ sweat check valve (with spring) (for use in
oil return line).
One 3/8” charging valve adapter with copper ferrules
and cap.
One 1/2” charging valve adapter with copper ferrules
and cap.
Two 5/8” charging valve adapters with copper ferrules
and cap.
One 3/4” to 5/8” reducing flare union (for use with
charging valve adapter if necessary).
One 5/8” to 1/2” reducing flare union (for use with
charging valve adapter if necessary).
One 1/2” to 3/8” reducing flare union (for use with
charging valve adapter if necessary).
One 1/4” NPT run brass fitting (fitting with Schrader
valve for use with oil adapter fitting for leak testing.)
One plastic tool for inserting power line into electrical
terminal block.
One brass three-way internal branch tee and copper
ferrule.
Two 1/4” NPT to 1/4” brass flare fittings.
Two 1/4” NPT to 1/4” brass 90-degree flare fittings.
Two 1/4” NPT pipe plugs
Twelve 1/4” flare nuts
One six feet length of 3/8” ID 3/4” line insulation
One ten feet length of 1/8” adhesive-backed insulation
tape.
One 18” x 24”x 1/2” sheet of adhesive-backed
insulation
Field-Provided Items
To be furnished by the installer:
PureCharge unit mounting hardware.
Electrical conduit and wiring materials.
1/4-inch copper refrigerant tubing.
Refrigerant cylinder (for collection of excess oil if
excess oil is not initially returned directly to the
chiller’s oil sump.
Preliminary Inspection
Before installing the PureCharge unit, check the data on
the unit nameplate and verify that it is the appropriate
model for the refrigerant in the chiller it is to be installed
on. Make sure the voltage is correct for the application.
Visually inspect all components for damage in shipment
before installing. Pay particular attention to the
Temperature Sensor (TS-1) capillary tube.
4 IM 856-1
PureCharge Unit Operational Overview
The PureCharge unit is designed to remove oil, acids and
moisture from a centrifugal chiller’s refrigerant. However,
its main purpose is to remove oil from the refrigerant and
return it to the chiller’s lubrication circuit (oil sump) where
it belongs. Initial oil stripping is accomplished in two
phases. The first phase, or initial oil stripping process,
occurs at initial start-up of the PureCharge unit. This is
when all the excess oil that has been added to the system
over time is removed from the oil sump and discarded.
Often times the initial stripping process can yield several
gallons to multiple tens of gallons, depending on how
severely the refrigerant is saturated with oil.
The second phase begins when all excess oil has been
removed from the refrigerant. The PureCharge unit will,
from that point on, maintain the system in lubrication
balance. Lubrication balance meaning virtually 100
percent of the compressor’s lubricating oil is kept in the oil
sump.
Operation of the PureCharge unit is accomplished by a
patented process utilizing gravity, heat and pressure in
conjunction with special high capacity desiccants to
completely remove oil, acids and moisture from a chiller’s
refrigerant charg e.
The PureCharge unit works by repeatedly drawing 10 to 20
pounds (depending upon the refrigerant level available in
the chiller evaporator) of refrigerant for processing from
the chiller for each extract cycle. The oil-contaminated
refrigerant is heated by means of a flexible band electric
heater and the liquid refrigerant is vaporized off. As the
refrigerant vaporizes it passes through the special E-Z
Change high capacity moisture/acid filter-drier where it is
cleaned before returning to the chiller evaporator.
At the end of the distillation phase, any distilled oil is
automatically returned to the chiller’s oil sump through an
in-line high acid capacity filter-drier where any residual
acids are removed.
The PureCharge unit is able to process between 850 and
1250 pounds of refrigerant per week.
Three Operational Phases:
1. Fill Phase (Phase 1): Refrigerant contaminated with
oil, acid and moisture flows by gravity from the
chiller’s evaporator into the PureCharge distillation
tank. The Fill Cycle terminates automatically when
liquid refrigerant is sensed by the optical level sensor,
or after 75 minutes fill time, whichever comes first. At
the end of the Fill Phase, Distillation (Phase 2) is
initiated.
2. Distillation (Phase 2): During the distillation phase the
distillation heater is energized, heating the refrigerantoil mixture and causing the liquid refrigerant to
vaporize. The vaporized refrigerant vapor flows from
the distillation tank to the chiller evaporator through
an integral high capacity moisture/acid filter-drier.
Once all refrigerant is vaporized, any distilled oil
remaining accumulates at the bottom of the
PureCharge distillation tank where it is further heated.
Upon reaching 155 F degrees an Oil Return Phase
(Phase 3) is initiated. Average duration of a typical
Distillation Phase is approximately 1-1/2 to 2-1/4
hours, depending upon the refrigerant level in the
distillation tank at the start of the distillation phase.
3. Oil Transfer (Phase 3): During the oil return phase
distilled oil is automatically transferred from the
Distillation Tank to the chiller’s oil sump. The
returning oil flows through an in-line high acid
capacity filter where residual acids are removed
before entering the oil sump.
How the PureCharge Unit Transfers Oil to the Chiller’s Oil Sump
During the Distillation Phase, vaporized refrigerant is
returned to the chiller evaporator through a 10-psid check
valve. Therefore, at the conclusion of the distillation phase,
the vapor pressure in the distillation tank will be at a
pressure 10 psi higher than the chiller evaporator / oil
sump pressure. This pressure is used to push accumulated
oil from the tank back to the oil sump.
How It Works
PureCharge operation is cyclic and non-stop as long as
power is applied. Each complete extract cycle comprises
three operational phases and is approximately 2-1/2 to 31/2 hours in duration.
IM 856-1 5
Operating Parameters
1. Fill Phase: 75 minutes maximum. (Controlled by
either programmed time or liquid level sensor.)
2. Distillation Phase: Duration of the Distillation Phase
is dependant upon the amount of refrigerant in the
tank at the conclusion of the Fill Phase and will vary
from approximately 1-1/2 to 2-1/4 hours.
3. Oil Transfer Phase: The Oil Transfer Phase is a six-
minute timed cycle.
4. Oil Temperature: The temperature of the distilled oil
is limited to 155 F degrees by Temperature Sensor
(TS-1). This setting can be calibrated in the field when
necessary. However, do not change the factory setting
unless calibration is absolutely necessary. Refer to the
Maintenance section for calibration instructions.
5. Refrigerant Process Capacity: The PureCharge unit ,
on average, processes approximately 850 to 1250
pounds of refrigerant per week. The chiller’s total
refrigerant charg e is processed and made
progressively cleaner until all oil, acids and moisture
have been removed. To completely clean the
refrigerant, the chiller’s total refrigerant charge must
be processed several times (at least 4 or 5 times).
6. Oil-Refrigerant Separation Efficiency: The amount of
refrigerant and oil being returned to the oil sump at the
completion each cycle is proportionate to the level of
oil concentration in the refrigerant. The higher the oil
concentration, the more refrigerant will be returned
with the oil to the oil sump. However, under any
condition, the amount of refrigerant reaching the oil
sump is insignificant. For example, a chiller with a
500-pound charge containing an average of 12% oil
by weight means that the PureCharge unit will return
approximately one pound of oil and approximately
two ounces of refrigerant to the chiller oil sump on
any given cycle. This is only during the initial cleanup period.
7. Once the excess oil is removed, only trace amounts of
refrigerant (if any) will ever reach the oil sump
because only a small amount of oil will be returned
during each return cycle (again that is once the excess
oil has been removed). The approximately two
ounces of refrigerant that does reach the chiller oil
sump every 2-1/2 to 3-1/2 hours is inconsequential
and will have no bearing on chiller operation if the
chiller’s oil sump heater is on. If on, the chiller’s oil
sump heater will quickly vaporize such a miniscule
amount of refrigerant long before the next PureCharge
unit’s oil transfer cycle occurs.
8. Power Consumption: Distillation is accomplished by
means of a 350-watt electric heater. However, because
the heater is only energized approximately 60% of the
time, power consumption is approximately that of a
250-watt light bulb.
Operational LED Indicators
A series of six LED indicators located on the upper right
side of the solid state logic board are provided as a means
of monitoring unit operation. See Figure 6 o n page
Operation LED indicators
D1, D2, D3, D4, D5 Green LED Blinking Indicates 5
second delay before program starts.
D1 Green LED Blinking Indicates unit is in Fill
Phase 1 and the distillation tank is currently being filled
from the chiller evaporator. The Fill Phase is either a 75minute timed period
6 IM 856-1
or until a liquid level high signal is
18.
received from the optical level sensor of the PureCharge
unit, whichever comes first.
D2 Green LED Blinking Indicates the cycle has
advanced to Distillation Phase 2 and is currently in the
process of vaporizing the refrigerant from the
refrigerant/oil mixture.
D3 Green LED Blinking Indicates the liquid
refrigerant has vaporized, distilled oil temperature has
reached 155 F degrees and is currently in the Oil Transfer
Phase 3.
D4 Green LED ON Solid Anytime the heater is on,
the green LED D5 will be on solid. This is simply for
informational purposes.
D5 Green LED On Solid Anytime the liquid level
high sensor senses a liquid level the green D5 LED is on
solid. This is simply for information.
Diagnostic LED indicators
When diagnosing unit problems it is helpful to be able to
verify various system components for proper operation.
(See the section titled Using Switch SW2 Dip Switches as
Diagnostic Aid on page
24.)
Fault LED indicators
The LED indicators are also used to indicate certain Fault
conditions. (Refer to the Troubleshooting Section starting
on page
fault conditions:
D6 Red LED Blinking with D1 Green LED ON
Solid: Indicates temperature in the distillation tank did not
drop below 155 F degrees within a pre-programmed time
limit of 20 minutes after initiating a Fill Phase. Refer to
Troubleshooting Section starting on page
cause.
D6 Red LED Blinking with D2 Green LED ON
Solid: Indicates temperature failed to reach 155 degrees F.
within a pre-programmed 6 hour time limit after initiation
of the Distillation Phase. Refer to Troubleshooting Section
starting on page
D6 Red LED Blinking with D3 Green LED ON
Solid: Indicates that the unit prematurely reached a
temperature of 155 F degrees during the distillation phase.
This would indicate that the distillation tank is not filling
with refrigerant properly or is losing the distillation charge
prior to proper distillation. Refer to Troubleshooting
Section on page
D6 Red LED Blinking with D4 Green LED ON
Solid: Logic board received a signal from the Liquid
Level High Optical sensor for a period of 2 hours straight
indicating a problem Refer to Troubleshooting Section on
page
24.) The following is a description of the possible
24 for probable
24 for probable cause.
24 for probable cause.
24 for probable cause.
Recording the LED Lights During a Fault
When you see the red FAULT light ON, do not
immediately turn the power switch OFF. First, remove the
cover from the control box and observe and record which
of the LED light(s) are ON. This will tell you the kind of
fault that has occurred. Turning the switch OFF resets the
logic board, terminating the Fault indicator. Record the
type of fault. Examine the unit for any apparent problems,
and check the troubleshooting section for possible causes
of the fault. If there is no readily apparent problem, reset
the unit. After reset, allow unit to operate normally to see
if the fault repeats.
IM 856-1 7
Installing the PureCharge Unit
3. The unit
(vertical) position.
must be installed standing in an upright
Location and Mounting
The PureCharge unit comes mounted on its own integral
base sufficient for proper support. Unit piping normally
provides adequate support to stabilize the unit. Additional
support may be provided as deemed necessary.
1. The unit
chiller’s refrigerant charging valve or other
appropriate valve located near the bottom of the
evaporator. The liquid refrigerant Fill Line is to be
connected at this point.
2. The unit should be mounted directly on the flo or so
the liquid refrigerant Fill inlet port is as low as
possible relative to the refrigerant level in the
evaporator. When the chiller is mounted on a pad, the
unit still should sit on the floor. The extra height of
the pad provides additional liquid head to aid in
gravity flow of liquid refrigerant from the chiller. The
unit cannot overfill because of a Liquid Level High
optical sensor. When the sensor is reached, the fill
phase is terminated.
During a Fill Phase, if the refrigerant level in the
distillation tank does not reach at minimum the
middle sight glass, the PureCharge unit is not filling
to an acceptable operating level.
Figure 1 – PureCharge Unit Hook-up
must be located within four (4) feet of the
! WARNING
Plumbing the Unit
To facilitate connection of the refrigerant Fill line and the
Oil Return line, to their respective chiller valves, special
brass valve adapter fittings and copper ferrules have been
provided in the Installation Kit. These special adapters
allow hook-up to the chiller’s valves without interfering
with normal service access.
Determining Which Side Port to Use
Each valve adapter has opposing 1/4-inch FNPT side ports.
To determine which of the ports to use, temporarily screw
the valve adapter onto the charging valve hand tight.
Usually only one of these ports will be accessible. This is
the port you will use. The other port will be plugged.
Select the appropriate fitting from the Kit, as called for in
the piping instructions, and install in this port. Then, using
a 1/4-inch pipe plug from the Kit, plug the unused side
port.
Each valve adapter comes with flare cap and ferrule to cap
off the adapter’s charging access port. Be sure to always
use a ferrule when installing the valve adapter and cap.
! CAUTION
Complete Fill Line and fittings from evaporator to
the PureCharge unit must be completely insulated
to avoid vapor locking, which will prevent filling.
1/4" Vapor Return Line
(Equalization Line)
Equalization Solenoid Valve (SOL-2)
Valve Adapter
1/4" Fitting
Refrigerant Charging Valve
1/4" Refrigerant "Fill" Line
Cap
Inlet Strainer
Evaporator Gauge Line
1/4" Internal Flare Branch Tee
Insulation
Fill Solenoid Valve (SOL-1)
EVAPORATOR
Oil Return Solenoid Valve (SOL-3)
"High Acid Capacity"
Oil Filter
1/4" Oil Return Line
Oil Sump
Oil Charging
Valve
Adapter
Valve
Shrader Fitting
Cap
Oil Line Check Valve
8 IM 856-1
Liquid Refrigerant Fill Line (with Strainer)
Although the following instructs you to connect the Liquid
Refrigerant Fill Line to the chiller’s refrigerant charging
valve, this is not always best. Some chillers have the
charging valve located very close to where liquid
refrigerant from the condenser enters the evaporator.
Usually, when this is the case, the chiller manufacturer
provides an alternate access valve elsewhere near the
bottom of evaporator. When this is the case, you should
connect to the alternate valve. If the chiller currently has
an oil recovery eductor system, it probably will be
necessary to disconnect the eductor and make the
connection there. Wherever the connection is made, as
long as sufficient refrigerant from the evaporator is
available to the unit, it will function and remove oil from
the refrigerant. However, connecting to the optimum
location assures optimal oil removal.
Carrier Series D™ Centrifugal Chiller Instructions
On some Carrier Series D centrifugal chillers, the
refrigerant charging valve is located about even with the
refrigerant level in the cooler. Therefore, for the unit to fill
by gravity, it will be necessary to cut into the horizontal
section of the refrigerant charging line where it exits the
bottom of the cooler and add a fitting and valve for
connection of the unit Fill Line.
1. Select the appropriate size valve adapter from the
Installation Kit that fits the chiller’s refrigerant
charging valve. Depending on how the Fill Line is to
run, select either a straight (U1-4B) or 90 degree (E14B) brass 1/4” NPT x 1/4” flare fitting from the Kit
and install in the appropriate side port. Install a 1/4”
pipe plug from the Kit into the opposite side port.
2. Using the appropriate copper ferrule, permanently
install the valve adapter onto the chiller’s refrigerant
charging valve. (See Figure 1, page
3. Using 1/4” O.D. copper tubing, run a 1/4” copper line
to the Fill Solenoid Valve (SOL-1) from the valve
adapter fitting. (See Figure 1, page
4. Be absolutely sure to keep the Fill Line lower than the
Liquid Fill Inlet connection on the distillation tank. If
any part of the Fill Line rises higher than the Fill Inlet,
liquid refrigerant may not flow by gravity from the
chiller into the distillation tank.
5. Next, from the Installation Kit select the Fill line
strainer and two 1/4” flare nuts and install anywhere
in the Fill Line. Make certain the connections to the
strainer are leak tight.
6. Before making final connection to the unit, insulate
the entire refrigerant fill line and strainer. Insulation
materials have been included in the Installation Kit.
IM 856-1 9
8.)
8.)
The entire Fill Line, Strainer, the refrigerant charging
valve and all interconnecting piping up to the
evaporator shell must be insulated. Failure to
properly insulate these items may cause vapor lock
preventing the PureCharge unit from functioning.
(See Figure 1, on page
7. Do not open the refrigerant charging valve at this
time.
Vapor Return Line
Note: When connecting the vapor return line to a Schrader
valve fitting, the valve stem
1. Close the evaporator gauge stop valve.
2. Disconnect the gauge line from valve.
3. From the Installation Kit, select the1/4”brass T6-4
three-way internal branch tee and copper ferrule.
Connect the tee to the gauge stop valve 1/4” port.
(See Figure 1, page
4. Re-connect gauge line to one end of tee.
5. From the other end of the tee, run a 1/4” copper line
to the Equalization Solenoid Valve (SOL-2). (See
Figure 1, page
Avoid sagging or traps in the Vapor Return
(Equalization) Line where vapor can condense and
accumulate causing a blockage
6. Do Not re-open evaporator gauge valve at this time.
Oil Return Line and Oil Filter-Drier installation
Based on the severity of oil contamination in your system,
the amount of oil that will be removed by the PureCharge
unit on initial start-up could be several gallons more
(excess oil) than the capacity of your chiller’s oil sump.
For example, a 500-pound refrigerant charge with 12% oil
by weight will contain approximately 8.5 gallons of excess
oil. Until the chiller’s refrigerant is free of oil, you must
decide how you are going to deal with the excess oil before
the initial start-up of the PureCharge unit.
The above example is for illustrative purposes only. A
smaller refrigerant charge with a higher percent oil
concentration, or a larger refrigerant charge with a lower
percentage, may yield much more than 8.5 gallons of
excess oil. Before proceeding, estimate how much excess
oil you will accumulate. To estimate the excess oil you are
likely to accumulate, refer to the most recent refrigerant
analysis for your chiller. You will also need to know the
weight of your chiller’s refrigerant charge. Then refer to
Chart 1, Percent of Oil, on page
approximately how much excess oil you will be dealing
with, you have the following two options as described.
! WARNING
8.)
must be removed.
8.)
8.)
10. Once you know
! CAUTION
It is important to note that the percentage of oil in a
sample can vary by as much as 10 percent
depending upon where the oil sample is taken from
the chiller. For example, if the sample is taken from
a location near where the refrigerant is returned
from the condenser, mostly pure refrigerant is being
returned to the evaporator at that location and the
sample will indicate a lower percentage of oil
contamination than actually exists in the chiller.
Option 1: Plumb the Oil Return Line per Option 1 piping
instructions on page
11. This option allows the excess oil,
as it is being stripped from the refrigerant, to flow direct to
the chiller’s oil sump where it can accumulate. With
Option 1, it will be necessary to periodically monitor the
sump’s oil level and remove excess oil as it accumulates.
Once the initial oil stripping process is complete and all
excess oil has been removed from the oil sump, further
monitoring will no longer be necessary.
Advantage: once the initial oil stripping process is
complete, no further action is required.
Disadvantage: the main disadvantage to Option 1 is the
necessity for someone to periodically monitor and drainoff oil from the oil sump. This may be inconvenient, as
the oil-stripping process may take days or weeks to
complete.
Option 2: Plumb the Oil Return Line per Option 2 piping
instructions on page 11. As determined by previous
calculation, install sufficient containment capacity, such as
a single 50, 100, 200, etc., pound refrigerant recovery
cylinder, in the Oil Return line between the PureCharge
unit and the chiller’s oil sump. The cylinder will retain
and hold the excess oil as it is stripped from the
refrigerant, preventing it from accumulating in the oil
sump.
Note that the rated capacity of a refrigerant recovery
cylinder is for refrigerant which is heavier than oil;
therefore a refrigerant recovery cylinder will not hold the
same weight of oil as the rated refrigerant capacity. (See
Figures 2 and 3 on page 11 which includes approxi mate oil
holding capacities of various size refrigerant recovery
cylinders.) Once the stripping process is complete the
cylinder and excess oil must be removed from the system.
Advantage: does not require periodic monitoring and
draining of oil in order to maintain proper oil level in the
oil sump. (Good practice is still to periodically monitor
the accumulation of oil in the recovery cylinder in the
event that there is more oil recovered than anticipated.)
Disadvantage
: requires temporary installation of a
containment vessel. Also, once the oil stripping process
is complete and the excess oil is collected, the
containment vessel must be removed from the system.
Use the chart below to estimate the amount of excess oil in
the chiller’s refrigerant charge. According to ASHRAE
Study 601-TRP, the average chiller has 12% oil by weight
in its refrigerant charge. A 500–pound refrigerant charge
at 12% by weight contains 60 lbs, or 8.5 gallons of oil.
Chart 1 – Refrigerant-Oil Contamination Chart
100 200 300 400 500 600 700 800 900 1000 1100 1200
% OIL Lbs. Of Oil in Refrigerant Charge based on % by weight
1%
2%
3%
4%
5%
6%
7%
8%
9%
10%
11%
12%
13%
14%
15%
16%
17%
18%
19%
20%
21%
22%
23%
24%
25%
1 2 3 4
2 4 6 8
3 6 9 12
4 8 12 16
5 10 15 20
6 12 18 24
7 14 21 28
8 16 24 32
9 18 27 36
10 20 30 40
11 22 33 44
12 24 36 48 60 72 84 96 108 120 132 144
13 26 39 52 65 78 91 104 117 130 143 156
14 28 42 56 70 84 98 112 126 140 154 168
15 30 45 60 75 90 105 120 135 150 165 180
16 32 48 64 80 96 112 128 144 160 176 192
17 34 51 68 85 102 119 136 153 170 187 204
18 36 54 72 90 108 126 144 162 180 198 216
19 38 57 76 95 114 133 152 171 190 209 228
20 40 60 80 100 120 140 160 180 200 220 240
21 42 63 84 105 126 147 168 189 210 231 252
22 44 66 88 110 132 154 176 198 220 242 264
23 46 69 92 115 138 161 184 207 230 253 276
24 48 72 96 120 144 168 192 216 240 264 288
25 50 75 100 125 150 175 200 225 250 275 300
CHILLER REFRIGERANT CHARGE BY WEIGHT IN Lbs.
5 6 7 8 9 10 11 12
10 12 14 16 18 20 22 24
15 18 21 24 27 30 33 36
20 24 28 32 36 40 44 48
25 30 35 40 45 50 55 60
30 36 42 48 54 60 66 72
35 42 49 56 63 70 77 84
40 48 56 64 72 80 88 96
45 54 63 72 81 90 99 108
50 60 70 80 90 100 110 120
55 66 77 88 99 110 121 132
Oil weighs approximately 7 lbs per gallon
60 Lbs = approximately 8.5 gallons
10 IM 856-1
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