VS8510/VS8520/VS8521
Millivolt Combination Gas Control
VS8520A
VS8520D
The VS8510 and VS8520 Combination Gas Control is a lowcapacity, compact-sized, millivolt-operated gas valve designed for
use in small gas appliances that burn either LP or natural gas.
Primary appliance applications include gas fireplaces, fireplace
inserts, log sets, free standing stoves, wall furnaces and room
space heaters. They offer basic On/Off control with a standard
regulator, and optional adjustable High/Low regulators.
■ VS8520 valve has operator powered by 750 mV thermopile
and power unit powered by 30 mV thermocouple.
■ Vented and vent-free models.
■ Available with standard or high/low regulators.
■ Adjustable servo regulator maintains constant gas outlet
pressure over a wide range of gas supply pressures.
■ Multiple inlet and outlet pipe connections with 3/8” NPT or
BSP threads.
■ Multiple pilot and thermocouple locations on inlet side and
bottom.
■ ECO (Energy Cut-Off) Connector option.
■ Optional Piezo ignitor on valve top.
■ Compact size.
The VS8510 and VS8520 Millivolt Combination Gas Valves are
approved in accordance with IAS (AGA/CGA).
FEATURES
Enhanced Safety for the Consumer.
■ For use with 750 mV thermopile generator utilizing selfpowered millivolt technology.
■ Programmed lighting sequence with safe lighting pilot
system and safety shutoff.
■ Latching device interlock eliminates involuntary re-ignition
of the main burner.
■ Fine mesh inlet screen (optional for outlet screen).
■ Snap-opening characteristics.
More flexibility and completeness in both the design and use
for the OEM (Original Equipment Manufacturers).
■ VS8510 valve has operator and power unit powered by 750
mV thermopile generator.
Copyright © 1997 Honeywell Inc. • All Rights Reserved
Easier installation and servicing by the dealer.
■ Multiple mounting holes and supports hook.
■ Pilot flow adjustment on top of valve.
■ European style inlet and outlet pressure taps on top of
valve.
■ White lettering on the pilotstat and high/low knobs, and
electrical connections.
■ Natural and LP gas spring conversion kits for standard
regulator models.
Easy use by the Consumer.
■ Pilotstat and high/low functions are separate knobs.
■ Non-reflective top of valve (all Black top plate and screws).
■ 3” plastic extension adaptor for pilotstat and high/low knobs.
70-2216
SPECIFICATIONS
SPECIFICATIONS VS8510, VS8520 AND VS8521
Models: VS8510, VS8520 and VS8521
Dimensions:
See Fig. 1
HI/LO REGULATOR
ADJUSTMENT
PILOTSTAT KNOB
4-5/8
(118)
4-9/16
(117)
SIDE
OUTLET
SIDE PILOT
OUTLET
3-7/32
(81)
17/32
(13)
MOUNTING
SCREW
SIZE 10-24
MOUNTING
SCREW
SIZE 10-24
M5X0.8
1-49/64 (45)
TO
THERMOSTAT
LO
25/64
(10)
ECO
WINDOW
BOTTOM
4-1/8 (104)
OUTLET
PRESSURE
TAP
5/16 (7)
2-7/32 (57)
TOP
TO THERMOPILE
SIDE
THERMOCOUPLE
CONNECTION
5-1/32 (128)
1-5/8 (41)
INLET
PRESSURE
TAP
BOTTOM THERMOCOUPLE CONNECTION
BOTTOM
INLET
BOTTOM
OUTLET
SIDE
OUTLET
HI
1
(25)
TO THERMOSTAT
11/16 (17)
1-3/16
(30)
15/16
(24)
5/16 (7)
1-1/4
(32)
17/32
(14)
1-1/8 (28)
M12667
BOTTOM
PILOT
OUTLET
2-9/16 (65)
Fig. 1. VS8510, VS8520 and VS8521 dimensions in. (mm).
70-2216
1-11/32
(34) 13/16
(20)
2
15/16 (24)
1-29/32 (48)
VS8510/VS8520/VS8521
Pressure Regulation Capacities
Pressure Drop Capacity Curve—Natural Gas
(Two Curves—Red/Black):
Standard Regulator:
Element
In. WC
VS8510, 20—Natural Gas
3.0-5.0
LP Gas
8.0-12.0
Mobile Home
Custom
Pressure Drop (in. wc)
Natural Gas
Hi/Lo Regulator:
Element
In. WC
Natural Gas
2.0—
1.5—
1.0—
.5—
Btuh x 1K
3.0-3.7/1.2-2.5
LP Gas
—
20
40
60
Red = bottom inlet
9.0-12.0/3.5-6.5
80
100
120
Black = side inlet
M13082
Pressure Rating:
IAS rated to maximum 1/2 lb. psi inlet pressure.
IAS Rated Capacity:
60,000 Btuh at 1 in. wc pressure drop for side inlet.
50,000 Btuh at 1 in. wc pressure drop for bottom inlet.
Models VS8510, VS8520 and VS8521
Model Configurations:
NOTE: For a more detailed explanation of model OS number information refer to Fig. 7.
Model
(A Suffix)
Standard
Regulator
VS8510A
X
VS8510D
VS8520A
(2”)
Quick Dropout
Power Unit
X
X
X
X
X
X
VS8521D
(21”)
M8X1 Pilot
Connection
X
X
VS8520D
VS8521A
(1”)
Standard Power
Unit
(D Suffix)
High/Low
Regulator a
X
X
X
a A field convertible High/Low regulator model will be available at a later date.
Other Characteristics
Safety Valve Configurations:
Q313 Thermopile powers safety valve and operator: vented.
Q335 Thermocouple powers safety valve and Q313
Thermopile powers operator: vented.
Thermocouple powers safety valve in oxgen depletion sensor
(ODS): vent free.
Pilot Gas Flow:
Connection Size:7/16-24 UNS.
Flow 1700 Btuh at 11 in. wc pressure drop.
Option M10x1 connection.
Pilot Location:
Inlet side or bottom.
Connection size: 7/16-24 UNS thread or M10X1 threads.
Thermocouple Connection (for fast dropout configuration):
Connection Size: 11/32-32 UNS double lead or M10X1 metric
threads option for vented.
Available in side or bottom outlet.
M8X1 for use on vent-free applications.
Temperature Rating:
0°F to 175°F (-18°C to 80°C).
Option for -40°F to 175°F (-40°C to 79°C), 0°F to 225°F (-18°C
to 101°C).
Screen:
Option for outlet screen.
Electrical Ratings:
30 mV power unit resets with a maximum of 300 mA applied
and dropout between 250 mA and 70 mA.
750 mV power unit resets with a maximum of 15 mA applied
and drop out between 7 mA and 3 mA.
Interrupter (ECO):
1/4 in. tab connectors.
Mounting:
Mounting support in eight locations On valve No. 10-24 screw.
Inlet and Outlet Connections:
–Inlet and outlet on side.
–Inlet and outlet on bottom.
–Inlet on side and outlet on bottom and on side.
–Inlet on bottom and outlet on side.
Certification:
International Approval Services: C2030022.
3
70-2216
OPERATION
STANDING PILOT MILLIVOLT VALVE OPERATION
Safety Valve and Main Valve are Closed
See Fig. 2 for a view of the millivolt valve gas distribution when the safety valve and the main valve are closed.
STANDING PILOT MILLIVOLT VALVE
OFF-POSITION (VALVES CLOSED)
ON
T
LO
PI
OFF
SERVO
REGULATOR
VENT
SUPPLY ORIFICE
SERVO
VALVE
MILLIVOLT
OPERATOR
PILOTSTAT
KNOB
MAIN VALVE
POWER
UNIT
Q313
THERMOPILE
ELECTRODE
MAIN BURNER
INTLET
OUTLET
PILOT TUBE
SAFETY VALVE
INLET GAS
Q377 PILOT
BURNER
CONNECT
THERMOPILE
LEADWIRES TO
GAS CONTROL
CONNECT ELECTRODE
LEADWIRE TO PIEZO
IGNITER
OUTLET GAS
WORKING GAS
Fig. 2. Safety valve and main valve are closed.
70-2216
4
M6811
VS8510/VS8520/VS8521
Safety Valve is Open and Pilot is Lit
See Fig. 3 for a view of the millivolt valve gas distribution when the safety valve is open and the pilot is lit.
STANDING PILOT MILLIVOLT VALVE
PILOT-POSITION (SAFETY/MANUAL VALVE OPEN)
ON
T
LO
PI
OFF
SERVO
REGULATOR
VENT
SUPPLY ORIFICE
MILLIVOLT
OPERATOR
SERVO
VALVE
PILOTSTAT
KNOB
MAIN VALVE
POWER
UNIT
Q313
THERMOPILE
ELECTRODE
MAIN BURNER
INTLET
OUTLET
PILOT TUBE
SAFETY VALVE
INLET GAS
OUTLET GAS
Q377 PILOT
BURNER
CONNECT
THERMOPILE
LEADWIRES TO
GAS CONTROL
CONNECT ELECTRODE
LEADWIRE TO PIEZO
IGNITER
M6812
WORKING GAS
Fig. 3. Safety valve is open and pilot is lit.
5
70-2216
OPERATION/ACCESSORIES/WIRING DIAGRAMS
Safety Valve and Main Valve are Open
See Fig. 4 for a view of the millivolt valve gas distribution when the safety valve and main valve are open.
STANDING PILOT MILLIVOLT VALVE
ON POSITION (VALVES OPEN)
T
LO
PI
ON
OFF
SERVO
REGULATOR
VENT
SUPPLY ORIFICE
MILLIVOLT
OPERATOR
SERVO
VALVE
PILOTSTAT
KNOB
MAIN VALVE
POWER
UNIT
Q313
THERMOPILE
ELECTRODE
MAIN BURNER
INTLET
OUTLET
Q377 PILOT
BURNER
PILOT TUBE
SAFETY VALVE
CONNECT
THERMOPILE
LEADWIRES TO
GAS CONTROL
INLET GAS
OUTLET GAS
WORKING GAS
Fig. 4. Safety valve and main valve are open.
70-2216
6
CONNECT ELECTRODE
LEADWIRE TO PIEZO
IGNITER
M6813
VS8510/VS8520/VS8521
Pilot Gas and Lighting Procedure
Q313
THERMOPILE
TARGET
MILLIVOLT
THERMOSTAT
1. Turn the knob clockwise to the PILOT position, Push down
on knob, and hold in position. The pilot valve opens and the
power unit armature makes contact with the electromagnet.
QUICK DROP-OUT
THERMOCOUPLE
ELECTRODE
2. Light the pilot burner, while continuing to hold down on knob
until a strong flame appears (approximately 60 seconds).
HIGH LIMIT
CONTROL
3. Release the knob. The shaft moves upward and opens the
safety valve lever.
4. Turn the knob to the ON position. On a call for heat, the
main burner ignites.
VS8520 HI/LO
MILLIVOLT
GAS VALVE
1. To shut off the system, turn the knob counterclockwise to
OFF. This closes the main gas and safety valve. The power
unit must drop out before the lighting sequence can begin
again.
T
LO
HI
ON
LO
PI
OFF
Shut Off Procedure
2. To relight the pilot light, follow the steps in the Pilot Gas and
Lighting Procedure section.
HI/LO
REGULATOR
GAS
CONTROL
KNOB
ACCESSORIES
Part Number
395991
395992
PILOT
ADJUSTMENT
SCREW
M12669
Fig. 5. VS8520 millivolt system wiring diagram
with quick drop-out thermocouple.
Description
Natural to LP Conversion Kit for standard
regulator.
MILLIVOLT
THERMOSTAT
LP to Natural Gas Conversion Kit for
standard regulator.
HIGH LIMIT
CONTROL
WIRING DIAGRAMS
Q313
THERMOPILE
See Fig. 5 for wiring diagrams for the quick drop-out
thermocouple model VS8520. See Fig. 6 for the standard Model
VS8510 without the quick drop-out thermocouple.
T
LO
HI
ON
LO
PI
OFF
VS8510 HI/LO
MILLIVOLT
GAS VALVE
HI/LO
REGULATOR
GAS
CONTROL
KNOB
PILOT
ADJUSTMENT
SCREW
M12668
Fig. 6. VS8510 millivolt system wiring diagram
without quick drop-out thermocouple.
7
70-2216
SPECIFICATION GUIDE
VS8510/VS8520/VS8521
VS85XX MODEL SPECIFICATION GUIDE
This reference matrix is a guide to help determine how the VS85xx products can be configured. When determining specific model
requirements, please refer to this diagram.
V
S
8
5
1
0
A
V
S
8
x
x
x
x
- A- STANDARD OPENER 0° to 175°
- D - HI/LOW REG 0° to 175°
- E - CONVERTIBLE HI/LO REG 0° to 175°
- M - STANDARD OPENER -40° to 175°
- Q - HI/LOW REGULATOR -40° to 175°
- R - CONVERTIBLE HI/LO REG. -40° to 175°
- K - STANDARD 0° to 225°
- L - HIGH/ LOW REGULATOR 0° to 225°
- N - CONVERTIBLE HIGH/ LOW 0° to 225°
- F - CONVERTIBLE 0° to 175° (Mobile Home)
- S - CONVERTIBLE -40° to 175° (Mobile Home)
- J - CONVERTIBLE 0° to 225° (Mobile Home)
- 0 - STANDARD PILOT MODEL
- 1 - VENT-FREE (M8X1 THERMOCOUPLE CONNECTION)
- 1 - 750 mV OPERATOR/750 mV POWER UNIT
- 2 - 750 mV OPERATOR/30 mV POWER UNIT
- 4 - Special
- 5 - STANDARD CAPACITY FOCUS VALVE
- 8 - LOW VOLTAGE
- S - MILLVOLT
- V - VALVE
M13086
Fig. 7. VS85xx O.S. Number configuration matrix.
Home and Building Control
Honeywell Inc.
Honeywell Plaza
P.O. Box 524
Minneapolis MN 55408-0524
Home and Building Control
Honeywell Limited-Honeywell Limitée
155 Gordon Baker Road
North York, Ontario
M2H 3N7
Honeywell Latin American Region
480 Sawgrass Corporate Parkway
Suite 200
Sunrise FL 33325
Honeywell Europe S.A.
3 Avenue du Bourget
1140 Brussels
Belgium
70-2216 10-97
70-2216
8
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paper containing at least 10%
post-consumer paper fibers.
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Sun Hung Kai Centre
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Wanchai
Hong Kong