Fieldpiece HG2 User Manual
O
Field Manual
Models: HG1 & HG2
Field Manual
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TM
HVAC GUIDE
Tester
Field Manual
HG1 & HG2
Do it right the rst time!
Minimize call-backs. Reduce testing and diagnosis time. Improve the technician’s technical capability.
Minimize reliance on outside technical help. e HVAC
TM
Guide
the most common HVAC tests. It then makes a diagnosis and recommends action. e HVAC Guide
makes the service call or installation faster, easier, cleaner, and more complete.
reasons for call-backs. It can cause compressor noise,
shorten compressor life, and lower capacity. Using the
built-in Superheat and Subcooling tests, the HVAC
Guide
step procedure to determine if the refrigerant charge
is correct. With the proper accessory heads, no calculations, charts, or data entry are needed.
that they are too hot or too cold. Once you’ve checked
the duct system for restrictions and leaks, adjust the air ow with the Target Evaporator Exit Temperature procedure that’s built into the HVAC Guide
cause your customers to call you and complain about
the temperature being too cold or the hot water not being hot enough. Use the Combustion test built into the
HVAC Guide
air/fuel mixture by analyzing the combustion products.
You can then make adjustments to make sure the equipment works as it should.
more sophisticated air conditioner test procedure that
will help diagnose more complex problems by looking
at the air conditioning system as a whole.
it more completely and avoid call-backs in the process.
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Guided Probe Tester can do all that and more.
e display leads the technician step by step through
TM
tester
Improper refrigerant charge is one of the primary
TM
tester leads the technician through a step by
Improper air ow can cause customers to complain
TM
tester.
An improperly adjusted furnace or water heater will
TM
tester to determine if you have the right
e CheckMe!® test (model HG2 only) is a much
Do it right the rst time, do it faster, do it easier, do
2
Table of Contents
Do it Right the First Time! . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Table of Contents. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
HVAC GuideTM Tester Controls . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Select the Test (Switch Positions). . . . . . . . . . . . . . . . . . . . . . . 6
Fill in the INPUT FORM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Read the OUTPUT FORM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
What Accessory Heads Do I Need? . . . . . . . . . . . . . . . . . . . . 10
How to Connect an Accessory Head. . . . . . . . . . . . . . . . . . . 11
Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Target Evaporator Exit Temperature . . . . . . . . . . . . . . . . . 12
Superheat. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Superheat and Subcooling FAQ part 1 . . . . . . . . . . . . 21
Subcooling. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Superheat and Subcooling FAQ part 2 . . . . . . . . . . . . 27
Combustion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
“CheckMe!®” . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Advanced Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
Memory (MEM). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
Units. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Customer ID. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Clearing a single input or INPUT FORM . . . . . . . . . . . . . . 52
Saving Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
Recalling Saved Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
Contrast Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
PC Software . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
Installing the PC Software . . . . . . . . . . . . . . . . . . . . . . . . . . 54
Communicating with a PC . . . . . . . . . . . . . . . . . . . . . . . . . . 55
Transfer Tests from the HVAC GuideTM Tester to a PC . . 56
Transfer Tests From the PC to the HVAC GuideTM Tester. . 58
Looking at Downloaded Data. . . . . . . . . . . . . . . . . . . . . . . 60
Other Operations with PC Software . . . . . . . . . . . . . . . . . . . 61
Air Conditioning Basics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
Combustion Basics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
Product Speci cations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
Limited Warranty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
Obtaining Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
Disclaimer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
John Proctor and Title 24 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
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© Copyright Fieldpiece Instruments 2007
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HVAC GUIDETM Tester Controls
Input Jacks
Connect accessory heads
here.
Input Button
Returns you to the INPUT
FORM.
Backlight Button
Turns on the backlight for
30 sec.
Arrow Buttons
Navigate within FORMS
and screens.
Switch Position Dial
Rotate to select test.
Clear Button
Clears a single input or
the entire INPUT FORM by
holding for 3 seconds.
Top View
Dot Matrix LCD Display
Displays INPUT FORMS and
OUTPUT FORMS.
Output Button
Triggers calculations and takes
you to the OUTPUT FORM.
Enter Button
Makes a selection or enters
data.
Battery Cover
After "POWER OFF" clears,
unscrew the two screws to
replace the 6AA batteries.
Save Button
Saves the current INPUT FORM.
Inputs are saved with Customer
ID and Time Stamp. See Saving
Data section for details.
Recall Button
Recalls previous tests within
each switch position. Previous
tests can only be accessed
through the switch position in
which they were performed
and are sorted by Customer ID
and Time Stamp.
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PC Cable Interface
PC cable plugs into the
bottom to transfer data.
Bottom View
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Select the Test
Switch Positions
MEM: Erase a single test, an entire customer’s set of
tests, or all data. MEM also allows you to check
memory status, rmware version, and communicate with a PC for data transfer.
TIME: Set current time and date for internal clock. All
tests are time stamped and cannot be changed later.
Target Evaporator Exit Temperature: By mea-
suring the return wet bulb and dry bulb, the HVAC
TM
Guide
temperature. To ensure that the A/C system has the
proper air ow per tonnage, the actual evaporator
exit temperature must be within ±3°F of the target
evaporator exit temperature as outlined in CA title
24.
Superheat: For a xed restrictor air conditioning sys-
tem, the HVAC Guide
bulb and outside dry bulb to calculate a target superheat and uses the suction line temperature and
pressure to calculate actual superheat.
tester calculates a target evaporator exit
TM
tester uses the indoor wet
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Subcooling: For a TXV/EXV air conditioning system,
the HVAC Guide
ture and pressure to calculate actual subcooling. If
the manufacture’s target subcooling is not available,
the HVAC Guide
estimate.
TM
tester uses liquid line tempera-
TM
tester provides a conservative
Combustion: For combustion equipment, the HVAC
TM
Guide
temperature and CO ppm to calculate %CO
tester uses %O2, ue temperature, primary
, % Ex-
2
cess Air, CO (air free), Net Temperature, Standard
E ciency and Siegert E ciency.
CheckMe!® (model HG2): is is a more advanced
test for determining the overall state of an air conditioning system. e CheckMe!® test will give you a
diagnosis of the system in plain English and a list of
potential problems in the system.
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Fill in the INPUT FORM
Read the OUTPUT FORM
Figure 1. INPUT FORM for the Superheat test.
e INPUT FORM lists parameters in the order of
expected entry.
ree ways to enter data:
1. Automatic: Attach appropriate head, select ap-
propriate line with the UP/DOWN arrows, press
ENTER to start measuring, and press ENTER
again to lock in the value.
2. Drop down menu: To change a parameter that
has a default, press RIGHT arrow or ENTER, use
UP/DOWN arrows to scroll through the drop-
down list, and press ENTER again.
3. Manual: Enter system data (or to enter test data
not taken with an accessory head) by pressing the
RIGHT arrow and then, character-by-character, use
the UP/DOWN arrows and the RIGHT arrow to
‘type in’ the value. When nished press ENTER. Tar-
get Evaporator Exit Temperature test has no system
data to enter.
Figure 2. OUTPUT FORM for the Superheat test.
To display the OUTPUT FORM, ll in the INPUT
FORM correctly and press the OUTPUT button or
scroll down. If the INPUT FORM is missing inputs, the
appropriate lines on the OUTPUT FORM will be blank.
If the data entered on the INPUT FORM is out of range
or physically impossible, an error message is displayed.
e OUTPUT FORM displays the results of the calculations.
• e “See Sec:” at the bottom of the OUTPUT FORM
tells you what section in the manual has more infor-
mation about how to perform the speci c test and
what the results mean.
• To ensure that your changes have optimized the sys-
tem, retest a er the system is stabilized.
e CheckMe!® test (model HG2) has a more detailed OUTPUT FORM. If everything on the INPUT
FORM is lled out properly, the CheckMe!® OUTPUT
FORM will rank the possible problems in order of likelihood and describe how to x them. If you haven’t taken
all the necessary measurements, the rst line will tell
you what you need to do for a complete diagnosis.
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What Accessory Heads
Do I Need?
Refer to the chart below to nd the recommended accessory head and thermocouple for each measurement. Automatically input measurements with
Fieldpiece accessory heads for maximum accuracy, or
manually input from non-Fieldpiece test equipment.
How to Connect an
Accessory Head
AOX2
ADMN2
ASX14
ACM3
ATH4 on
HVAC Guide
TM
tester
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Tests
A-Coil
Fan
Dry Bulb and
Wet Bulb T/C
Supply Plenum
C
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er
1.1
Evaporator Exit Temperature gives you an indication of
the proper indoor air ow. is test can be easily performed simultaneously with superheat or subcooling
tests.
3°F above or below the Target Evaporator Exit Temperature, an air ow problem may exist. Ensure that lters are
clear, dampers are adjusted properly and the fan speed
is set correctly if it can be varied. e Target Evaporator Exit Temperature switch position uses the table from
California Title 24.
Target Evaporator Exit Temperature
For given return plenum air conditions, Target
If actual evaporator exit temperature is more than
Supply Plenum
Direction
of Air ow
Dry Bulb and
Wet Bulb T/C
Filter
Dry Bulb T/C
Fan
A-Coil
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Figure 3. Setting up the ATH4 and
HVAC Guide
TM
tester to measure dry
bulb and wet bulb temperatures
between fi lter and coil.
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1.2 Target Evaporator Exit Temperature
1.3 Target Evaporator Exit Temperature
INPUT FORM
Can be measured automatically with
Fieldpiece accessory heads.
Customer ID is useful for record keeping.
Units can be changed to either English
or Metric.
Figure 4. INPUT FORM for Target Evaporator Exit Temperature.
Into Evap Return Dry Bulb and Wet Bulb: Take
measurements as close to the inlet of the air handler
as possible. If the lter is just before the air handler,
the easiest way is to clip an ATWB1 and ATA1 to the
lter on the side facing the evaporator and take the
measurements. If the lter is not before the evaporator, make small holes in the return plenum just big
enough for the probes. Seal any holes before leaving
the jobsite.
Out of Evap Supply DB (dry bulb temp leaving
the evaporator): Measure in the center of the supply
plenum. Punch a small hole in the supply plenum
and insert a calibrated dry bulb thermocouple such
as the ATA1 or ATB1. Make sure the thermocouple
is in the center of the plenum cross-section. Seal the
hole when nished.
OUTPUT FORM
If Target and Actual are more than 3°F
apart a modification is needed.
Sections of manual with more
information about this test.
Figure 5. OUTPUT FORM for Target Evaporator Exit Temperature.
Press OUTPUT for the Target Evaporator Exit Tem-
perature OUTPUT FORM.
Target Evap Exit DB Temp (Target Evaporator
Exit Dry Bulb Temperature): is is the target exit
temperature based on the measured indoor conditions.
Actual Evap Exit DB Temp (Actual Evaporator
Exit Dry Bulb Temperature): is is the measured
temperature of the air in the supply.
e
Actual Evap Exit DB Temp should be
within ±3°F of the
the temperature is outside of this range, the technician
should make modi cations to correct the problem.
Target Evap Exit DB Temp. If
An Actual Evap Exit DB Temp below the
Target Evap Exit DB Temp indicates low air ow.
Increasing air ow can be accomplished by eliminating restrictions in the duct system, increasing blower
speed, cleaning lters or opening registers. A er corrective measures are taken, repeat measurement procedures as o en as necessary to establish adequate air ow
range. Allow system to stabilize for 15 minutes before
repeating measurement procedure.
1 2005 Residential ACM Manual, Page RD-5, (#5-7)
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An Actual Evap Exit DB Temp above the
Target Evap Exit DB Temp usually indicates low
capacity. Occasionally air ow is higher than expected.
Look for causes of low capacity such as refrigerant mischarge or dirty condenser coil. If the air ow is high,
correct by lowering the fan speed.
Because everything within the system is inter-dependent, one adjustment can a ect other parts of the
system. For example, increasing air ow increases the
superheat, which may require adding refrigerant. A er
modi cations, allow 15 minutes to stabilize and then
retest.
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2.1 Superheat
Superheat is the temperature rise above the boiling
point of the refrigerant a er the evaporator. Too high,
and the refrigerant boils o early in the evaporator and
‘wastes’ most of the capacity of the evaporator. Too low,
and you risk liquid going into the compressor.
Using superheat is the best way to obtain proper
refrigerant charge for a xed restrictor metering device
system.
If the air conditioner is in good working order and
the air ow is adjusted properly, comparing the actual
and target superheat will tell you if refrigerant needs to
be added or recovered. Ensure the pressure never exceeds the manufacturer's maximum overload pressure
guidelines.
On a xed restrictor system, the target superheat is
determined based upon the indoor wet bulb and outdoor dry bulb temperatures. Proper superheat ensures
the compressor doesn't ood under a low indoor load
and that the maximum e ciency and capacity are maintained.
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Figure 6. Using the ASX14 Superheat/Subcooling Head to gather suction line
temperature and pressure for the HVAC Guide
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TM
tester Superheat Test.
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2.2 Superheat INPUT FORM
Standard table uses the Title 24 target
superheat table.
Can be measured automatically with
Fieldpiece accessory heads.
Customer ID is useful for record keeping.
Figure 7. INPUT FORM for Standard Table Superheat Test.
Custom table allows you to enter your
own target superheat value.
Can be measured automatically with
Fieldpiece accessory heads.
Units can be changed to either English
or Metric.
Figure 8. INPUT FORM for Custom Table Superheat Test.
SH Table: Default: “Standard” uses the target super-
heat table from Title 24 for xed restrictor systems.
Other selection: “Custom” allows you to enter your
own target superheat by displaying the
input.
Target SH
air reaches the indoor coil). Wet the wet bulb sensor
(ATWB1) and insert it a er 15 minutes of continuous running. Clip downstream of the lter if the
lter is just before the air handler. Clip on the side
facing the evaporator and take the measurements.
If the lter is not before the evaporator, make small
holes in the return plenum just big enough for the
probes. Seal any holes before leaving the jobsite.
Watch the wet bulb temperature; it will drop and
then stabilize. e wet bulb temperature is the stabilized reading. If the sensor starts to dry out, the
reading will rise and the wrong temperature will be
recorded.
SL Pressure (suction line pressure): Connect the
ASX14 to the suction side service port. Select pressure mode on the ASX14 head. e system must be
stabilized before taking the measurements. Enter
data manually if you want to get pressure from your
gauges. e analysis is only as good as the measurements. e Fieldpiece ASX14 has better resolution
than most gauge sets.
Target SH (Custom SH Table): Change the SH Ta-
ble to Custom and enter the manufacturer’s recom-
mended superheat in the
Target SH input.
Refrigerant: Default: R-22. Other selections: R-410A,
R-134A, R-404A, R-407C, R-409A, R-408A, R-507A,
R-414B (Hotshot
(NU222B
TM
TM
), R-422C (OneshotTM), R-422B
) or R-12.
OD Dry Bulb (outdoor dry bulb, Standard SH Ta-
ble): Clip a calibrated ATA1 to the inlet of the con-
denser ns (typically on the side of the condenser),
in the shade if possible. Note that the temperature of
the air entering the outdoor coil can be considerably
di erent than the ambient temperature due to recir-
culation of air exiting the unit. Determine the aver-
age temperature of the air entering the condenser.
ID Wet Bulb (indoor wet bulb, Standard SH Table):
Take measurements very close or within the return
air side of the inlet to the air handler (not at the re-
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turn grill since temperatures change by the time the
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SL Temp (suction line temperature): Measure near SL
service port (within 6 inches). Use the ATC1, ATC2
or ATC3 to get a good pipe temperature. e clamp
should be perpendicular to the pipe and should be
securely seated with the sensor in contact with the
suction line. If working on a package unit make sure
you are at least 6 inches away from the compressor.
Figure 9. ATC1 pipe clamp thermocouple attached to a pipe correctly.
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2.3 Superheat OUTPUT FORM
Superheat and Subcooling FAQ
If Target SH and Actual SH are more than
5°F apart, as in this example, you need to
make adjustments to the system.
Boiling point is used to calculate Superheat.
Sections of manual with more information
about this test.
Figure 10. Superheat Test OUTPUT FORM.
Press OUTPUT for the Superheat OUTPUT FORM.
Target SH (Superheat): Indicates what the superheat
should be as calculated from outdoor dry bulb and
indoor wet bulb
Actual SH (Superheat): Shows the superheat calculated
from the measured suction line temperature and suc-
tion line pressure.
Boiling Point: is is the saturation temperature of the
refrigerant in the evaporator coil. It is one of the tem-
peratures from which superheat is calculated.
e
Actual SH (superheat) should be within ±5°F of
the Target SH to ensure optimum performance. If the
ac-
tual SH is outside this range, modi cations to the charge
or adjustments to the restrictor (TXV) are necessary.
Adding refrigerant lowers your Actual SH. Recovering refrigerant increases your Actual SH. e amount of
refrigerant necessary to add or recover will vary based on
the size of the system and the di erence between the Actual and Target SH.
Because everything within the system is inter-dependent, one adjustment can a ect other parts of the system.
For example, increasing air ow increases the superheat,
which may require adding refrigerant. A er modi cations, allow 15 minutes to stabilize and then retest.
Q: How do superheat/subcooling tools work?
A: Superheat tools measure suction line pressure and
suction line temperature, and calculate the actual superheat. Subcooling tools measure the liquid line pressure and liquid line temperature and calculate actual
subcooling. e refrigerant charts for calculations are
incorporated into the so ware of the HVAC Guide
tester.
TM
Q: When should I take my actual and target
superheat/subcooling?
A: Superheat and subcooling readings must be taken
when the system is in a steady state. Typically a residential system will be in a steady state a er 10-15 minutes. Turn the system on and set the thermostat low to
ensure that the system doesn’t turn o during your
testing. Once the system’s temperatures and pressures
are not uctuating, the system is in a steady state.
Wet bulb temperature, outdoor dry bulb, suction line
pressure and suction line temperature must be taken
within a short time period to ensure valid results.
Conditions that a ect your target superheat and target subcooling can change by the minute.
Q: What do I do with my ACTUAL superheat
or ACTUAL subcooling measurements?
A: Compare actual readings against the target superheat/
subcooling. As a general rule, if superheat is too high,
add refrigerant. If too low, remove refrigerant. If subcooling is too low, remove refrigerant. If subcooling is
too high, add refrigerant. Consult the manufacturer’s
speci cations before adding or recovering refrigerant
as further diagnostic tests may be needed
Continued on page 27
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3.1 Subcooling
Subcooling is the temperature decrease below the
boiling point (same as the condensing point) in the condenser. Too high, and refrigerant condenses too early in
the condenser and ‘wastes’ most of the capacity of the
condenser. Too low, and a mixture of gas and liquid can
be delivered to the expansion valve, reducing e ciency.
Subcooling is the best way to obtain proper refrigerant charge for a TXV/EXV system.
If the air conditioner is in good working order and
the air ow is adjusted properly, comparing the actual
and target subcooling will tell you if refrigerant needs
to be added or recovered (ensure the pressure never exceeds the manufacturer's maximum overload pressure
guidelines).
In a properly working TXV/EXV system, the superheat is held constant. Ensure the TXV/EXV bulb is installed properly, there is proper refrigerant to obtain target subcooling, and there are no liquid line restrictions.
Adjust refrigerant charge so that the actual subcooling is
within ±3°F of target subcooling.
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Figure 11. Using the ASX14 Superheat/Subcooling Head to gather liquid line
temperature and pressure for the HVAC Guide
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TM
tester Subcooling Test.
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