Field Controls PVU-300 User Manual

POWER VENTER SYSTEM

Model: PVU-300

Included is one ETL LISTED power venter to be used for side wall venting of a single 120/24 VAC controlled
furnace, boiler, or water heater which burns natural or LP gas, or oil. The PVU may also be used to vent a
single 24 VAC controlled gas fired furnace or boiler and a 30 millivolt residential gas fired water heate r.

TYPICAL VENTING SYSTEM COMPONENTS

ETL LISTED PVU-300 POWER VENTER with pre-wired integral Universal
Control (24VAC and 120 VAC), factory set Draft Proving Switch, and direct
access Terminal Blocks.

• Side Wall Vent Hood (Not included) • Spill Switches (Not included)

• Barometric Draft Control (Not Included)

C

ONTENTS PAGE

System Operation 2
Power Venter Sizing 2-3
Installation Safety Instructions 3-4
Installation of Power Venter 4-6
General Wiring Instructions 6
PVU Internal Wiring Schematic 6-8
Adjusting Thermostat Anticipator 8
Airflow Adjustments 9
General Installation Inspection 9
System Control Check Procedures 10
Troubleshooting Tips 10
Maintenance 10
Replacement Parts List 10
Multiple Venting Systems 11-13
Venting System Operational Information 15
Installation Information 15

This device MUST be installed by a qualified agency in accordance with the manufacturers installation
instructions.

The definition of a qualified agency is: any i ndividual, fir m, corporation or compa ny which eith er in pers on or through a repr esentative is
engaged in, and is responsible for, the installation and operation of gas ap pliances, who is experienced in such work, familiar with all
the precautions required, and has complied with the requirements of the authority having jurisdiction.

DO NOT DESTROY

THESE INSTRUCTIONS MUST REMAIN WITH EQUIPMENT

2630 Airport Road · Kinston, NC 28504

Phone: [phone]· Fax: [phone]

www.fieldcontrols.com

UNIT SPECIFICATIONS

(See Table 1 and Figure 1)

Table 1

UNIT DIMENSIONS (INCHES)

MODEL “H” “W” “D” I/O*

PVU-300

7.5 11.5 7.0 4/4

*

Inlet and outlet diameter.

ELECTRICAL RATINGS

MODEL VAC Hz RPM WATT AMP TP**

PVU-300

115 60 3000 145 2.1 YES

**

Thermally protected motor.

Figure 1

SIDEWALL VENT HOODS (Model SWH-1)

Sidewall vent hoods are available in the following sizes. The vent hood should be chosen that
matches the outlet size of the Power Venter. (See Figure 2) NOTE: When using different sizes
consider reducers and specific size pipe when determining equivalent length of vent pipe.

SWH-1-3 - 3 inch
SWH-1-4 - 4 inch
SWH-1-5 - 5 inch
SWH-1-6 - 6 inch
SWH-1-8 - 8 inch

SYSTEM OPERATION

Figure 2

1. The thermostat (wall thermostat, or aquastat) calls for heat and energizes a relay, which
activates the power venter. After the venter motor has come up to speed, the pressure switch closes. This completes
the circuit to the burner and allows the burner to fire.

2. For millivolt controlled water heaters, the gas pressure switch on the gas valve activates the power venter at the same
time as the burner fires.

3. After the heating requirement has been satisfied, the thermostat circuit will open and de-activate the burner and power
venter circuit.

4. The post purge timer continues to run the power venter for a period of time after the burner has shut off to purge
remaining flue gases.

POWER VENTER SIZING

In order to choose the correct size power venter for a particular installation, the total input firing rate and total equivalent
length of vent pipe to be used must be known. Refer to Table 2 to determine the maximum allowable equivalent feet of
pipe for each model used with the pipe diameters shown. When venting multiple appliances, add the input of each
appliance to determine the total input. Always choose a power venter that is capable of handling more than the system
requires. The choke plate can be adjusted to compensate for the difference.

Table 2

MAXIMUM EQUIVALENT HORIZONTAL PIPE

LENGTH (FEET)

VENTER MODEL NO. AND

VENT PIPE DIAMETER

BTU/HR INPUT

PVU-300

4” 5” 6”

100,000
145,000
220,000
310,000

305 --- --­145 247 334

64 100 147

--- 54 74

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ROCEDURE FOR CALCULATING TOTAL EQUIVALENT PIPE LENGTH IN FEET

P

1. Calculate the total equivalent feet for each type of fitting used in the venting system from the following chart.

2. Calculate the total amount of feet for the straight lengths of vent pipe.

3. Add the equivalent feet for the fittings with the total amount of feet of straight lengths.

Table 3

EQUIVALENT LENGTH (FEET) OF VENT PIPE FOR VENT PIPE FITTINGS

VENT PIPE FITTINGS

VENT PIPE DIAMETER

3” 4” 5” 6” 7” 8” 9” 10”

TEE
90° ELBOW
45° ELBOW

19 25 31 38 44 50 56 63

5 7 9 11 12 14 16 18
3 4 4 5 6 7 8 9

1/4 8 11 14 17 19 22 25 28

REDUCER

(d/D)*

1/2 5 7 8 10 12 13 15 17
3/4 2 3 3 4 4 5 6 6

*

Reducer or increaser ratio (d/D) small diameter divided by the larger diameter. (See Figure 3)

Example: 4" to 8" reducer, the reducer ratio is d/D = 4/8 = 1/2. To estimate the equivalent foot
length for the fitting, use the smaller pipe diameter for the equivalent length figure. Example:
4" to 8" reducer; the reducer ratio is 1/2 and the smaller pipe
diameter is 4". So, from the chart, the equivalent feet would be 7
feet.

Example: System Pipe Size = 4"

Step 1 2 – 90° Elbows (4") = 14 Ft.
Step 2 10 - 2 Ft. Lengths of 4" Pipe = 20 Ft.

Figure 3

Step 3 Total Equivalent Feet = 14 Ft. + 20 Ft. = 34 Ft.

INSTALLATION SAFETY INSTRUCTIONS
CAUTION: This device must be installed by a qualified installer in accordance with the manufacturer's installation

instructions. Appliances should have a minimum of 75% combustion efficiency or have a maximum measured flue gas
temperature of 550°F at the inlet of the venter.

1. The power venting system must be installed by a qualified installer. "Qualified Installer" shall mean an individual who
has been properly trained or a licensed installer. The installer must write or imprint his name, phone number and date
of installation on the installation tag. The tag should be attached to the power venter unit. Recording burner and
venting system initial operational information is recommended as a guide for service or burner tune-up. Enter this on
the back page of this manual.

2. Safety inspection of a venting system should be performed before and after installing a power venting system on an
existing or new appliance. Procedures to follow are those recommended by the National Fuel Gas Code,
A.N.S.I.Z223.1 or refer to the "General Installation Inspection" section of this manual.

3. Plan the vent system layout before installation to avoid the possibility of accidental contact with concealed wiring or
plumbing inside walls.

4. Single wall vent pipe may be used to join an appliance to the venting system, but if proper clearances cannot be
maintained from combustible materials, Class B Vent Pipe should be used for gas appliances. Refer to national or
local codes for guidelines. Also, a minimum of 6 inches clearance between the venter housing and combustible
materials must be maintained.

5. Disconnect power supply before making wiring connections to prevent electrical shock and equipment damage.

6. This equipment is designed to overcome minor negative pressure conditions. To ensure extreme negative pressure
does not exist, follow the "General Installation Inspection" section of this manual.

7. Heating appliances equipped with draft hoods, such as boilers or furnaces, LP and natural gas appliances SHOULD
have a secondary spillage switch installed. On appliances without draft hoods, it is recommended that the secondary
safety switch GSK-3 be installed into the system. Gas-fired 30 millivolt power systems MUST be equipped with a
spillage switch.

Page 3

8. Air flow adjustment MUST be made to ensure appliance efficiency. This should be done at the appliance exhaust
outlet with a velocity meter, draft gauge or by the "match test procedure". The match test is in accordance with
National Fuel Gas Code A.N.S.I.Z223.1, Section 8.6.

9. On heating appliances not equipped with a draft hood, a barometric draft control MUST be installed to regulate proper
air flow and fluctuations in the system's air flow during operation. Fluctuations can come from wind loads on the outlet
of the venter, house depressurization during windy days and the different house ventilation requirements between
summer and winter operation. Use a Field Controls Type MG-1 Barometric Draft Control. Gas-fired draft induced
systems should have a single-acting or double-acting barometric draft control installed.

Diagram A

INSTALLATION OF POWER VENTER
CAUTION: Failure to install, maintain and/or operate the power venting system in accordance with manufacturer's

instructions will result in conditions which may produce bodily injury and/or property damage.

1. Remove power venter from box and inspect unit for damage. If the carton has been crushed or mutilated, check unit
very carefully for damage. Rotate venter wheel to insure that the motor and venter wheel rotate freely. DO NOT install
if any damage is apparent. Refer to unit sizing chart to check proper venting sizing.

2. Location of the termination of the venting system should be installed in accordance with the National Fuel Gas Code,
A.N.S.I.Z233.1, manufacturer's recommendations, and/or local codes which are applicable. See the following
requirements or refer to Diagram A for typical locations.

a. The exit termination of mechanical draft systems shall

not be less than 7' above grade when located
adjacent to public walkways.

b. A venting system shall terminate at least 3' above any

forced air inlet located within 10'.

c. The venting system of other than a direct vent

appliance shall terminate at least 4' below, 4'
horizontally from, or 1' above any door, window, or
gravity air inlet into the building.

d. The vent termination of a direct vent appliance with an

input of 50,000 BTU/Hr or less, shall be located at
least 9" from any opening through which vented gases

Figure 4

could enter the building. With an input over 50,000

BTU/Hr, a 12" termination clearance shall be required.
e. The vent termination point shall not be installed closer than 3' from an inside corner of an L-shaped structure.
f. The vent termination should not be mounted directly above or within 3' horizontally from an oil tank vent or gas

meter.
g. The bottom of the vent terminal shall be located at least 12" above finished grade.

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SIDE WALL VENT HOOD INSTALLATION

1. Use the inside wall plate as a template to mark the hole location. Cut a hole 1 inch larger than the marked hole to
facilitate easy installation (See Figure 4)

2. Center vent hood through the hole from outside. Fasten the vent hood to the outside wall with the appropriate type of
mounting screws.

3. Fasten the wall end plate to the inside wall with the appropriate type of
mounting screws. NOTE: Apply sealant to the outside mounting plate of
the vent hood to prevent leakage.

4. Connect the venter outlet or a properly sized section of vent pipe onto
the inner pipe of the vent hood. Fasten the connection with three sheet
metal screws or equivalent fastening method.

5. Seal the vent hood inlet connection and any other vent pipe joints on the
outlet side of the venter with an approved high temperature silicone
adhesive sealant or equivalent material.

NOTE: Do not enclose the space between the plates on the outside of the

Figure 5

vent hood or between the inner and outer pipe of the vent hood. This might
cause overheating of the wall structure. Local codes might require

fencing around the vent hood outlet.

V

ENTER LOCATION

Install the power venter onto the vent hood inlet or as close to the vent
hood inlet as possible. Always install the venter such that the motor
shaft is horizontal and the pressure switch diaphragm is vertical (See
Figure 5) When venting a draft induced gas fired heating appliance a

Figure 6

barometric draft control must be installed on the vent system between
the appliance outlet and the venter inlet. (See Figure 6)

CAUTION: The power venter should never be installed with the motor shaft in the vertical position. This could allow heat
to be trapped in the venter housing and radiate through the motor possibly causing motor deterioration and premature
failure. Never attach the venter inlet directly to the outlet of the heating appliance. Also, a minimum of 6 inches clearance
between the venter housing and combustible materials must be maintained.

C

ONNECTING VENTER TO THE FLUE PIPE

NOTE: The power venter should be supported in accordance with National Fuel Gas Code Z223.1, Section 7.910 as

follows; A vent connector shall be supported for the design and weight of the material employed to maintain clearances
and to prevent physical damage and separation of joints.

NOTE: For gas fired heating appliances not equipped with a draft hood, a barometric draft control must be installed
between the heating appliance exhaust outlet and the power venter inlet to regulate any draft fluctuations during
operation.

1. Use approved vent connectors to join the heating appliance outlet to the venter inlet securing each joint with sheet
metal screws or equivalent means of fastening when required.

2. Seal all pipe joints on the outlet side of the venter with a high temperature silicone adhesive or equivalent. Test the
vent connections for leaks by using a soap solution as recommended by the National Fuel Gas Code, A.N.S.I. Z223.1,
Section 4.1.1.

Page 5