Johnson Controls GS-20 Series User manual

Installation Sheets Manual 121
Gas Combustion Combination Controls and Systems Section G
Technical Bulletin GS
Issue Date 0297
© 1997 Johnson Controls, Inc. 1
Part No. 24-8711-5, Rev. —
Code No. LIT-121895
Figure 1: GS Series Single-Block Multi-Function
Gas Control Valves
The GS Series single-block multi-function gas control valves provide for
protection and control of atmospheric and forced draft gas burners in
industrial and commercial heating installations. Optional sizing of body
flanges offers greater application flexibility. Valves are approved to
European and North American standards.
Typical applications include commercial and industrial boilers,
commercial and industrial burners and ovens, rooftop units, make up air
heaters, hot water heaters, kilns, and paint booths.
These single-block multi-function gas control valves offer single unit
control, replacing multiple components in a gas-train assembly, such as
on-off gas valves, gas pressure regulators, and modulating gas valves.
Options include adjustable start gas and slow open function, spring and
servo regulators, and gas/air ratio control.
GS Series
Single-Block Multi-Function Gas Control Valves
Application

2 G Gas Combustion Combination Controls and SystemsGS Series Single-Block Gas Control Valves
Table 1: Specifications
Types of Gas Natural and Liquid Petroleum (LP) Gas
Maximum Operating Pressure 5 psi (350 mbar)
Maximum Inlet Pressure 5 psi (350 mbar) on shutoff valves
3 psi (200 mbar) with pressure regulator
Maximum Differential Pressure 8 inches W.C. (20 mbar) (GS-_03_)
20 inches W.C. (50 mbar) (GS-405_ and GS-406_)
Permissible Ambient
Temperature 5 to 140°F (-15 to 60°C)
Body Connections Detachable flanges with pipe thread 3/8 inches to
1-1/2 inches NPT
Pressure Taps Flanges: 1/8 inch threads with plastic tube
fitting
Body: Standard is 1/8 inch (multi-position)
Special is 1/4 inch (multi-position) on
GS-4 only
Filter Segment Dirt Strainer: 0.02 inch (0.5 mm) mesh
Filter: 0.002 inch (0.05 mm) gauze
Valve Timings Closing Time: ≤ 1 second
Opening Time: <1 to 15 seconds
Dead Time: < 1 second
Operating Time Rating 100% Continuous
Coil Insulation Class Class F
Electrical Connections Standard Plug DIN 43 650, screw terminals inside
DIN plug
(Set Number GO-9101-0000, see separate
accessories.)
Table 2: Electrical Ratings
Valve Model Operating Voltages Power Consumption
GS-20_ _ 230 VAC +10/-15%, 50/60 Hz
120 VAC +10/-15%, 50/60 Hz
24 VAC +10/-15%, 50/60 Hz
18 VA
25 VA
21 VA
GS-40_ _ 230 VAC +10/-15%, 50/60 Hz
120 VAC +10/-15%, 50/60 Hz
24 VAC +10/-15%, 50/60 Hz
25 VA
27 VA
26 VA
Electrical
Ratings

GGas Combustion Combination Controls and SystemsGS Series Single-Block Gas Control Valve 3
!
CAUTION: This instruction sheet is intended as a guide for
qualified service personnel installing or servicing
Johnson Controls products.
!
WARNING: The system must meet all applicable codes. Improper
installation may cause explosions, property damage,
and injuries.
Carefully follow all instructions in this sheet and all instructions on the
appliance. Limit repairs, adjustments, and servicing to the operations
listed in this sheet or on the appliance.
!
CAUTION: Isolate the gas supply at the main manual shutoff
valve before installing the GS Series valve.
The GS Series valve may be mounted on a horizontal manifold with the
magnetic operator pointed up (vertical) or in any position not exceeding
90ofrom the vertical. The valve may also be mounted on a vertical
manifold in any position around its axis (see Figure 2). Do not install the
solenoid actuator upside down. Install vertically wherever possible.
90° Maximum
from Vertical
90° Maximum
from Vertical
Figure 2: GS Series Valve Mounting Position
The ambient temperature maximum must not exceed the specified limits
(see Table 1).
Check the power supply voltage for compatibility with the required valve
voltage. For valves with 24 volt coils, use only NEC Class 2 transformers,
such as the Johnson Controls Y65 transformer.
Note: The Y65 transformer must be mounted to a grounded metal
enclosure.
When installing the valve on the manifold, ensure the gas flows through
the valve body in the direction indicated by the arrow on the body. If the
valve is installed with the gas flow opposite the arrow, leakage can occur.
When installing the valve, mount the flanges to the pipe separately, then
mount the valve between the two flanges.
Installation

4 G Gas Combustion Combination Controls and SystemsGS Series Single-Block Gas Control Valves
An optional thread lubricant may have been factory applied to the first
two or three threads of the inlet and outlet to avoid galling. Use an
approved pipe joint sealing compound on male threads before assembly.
Take care to see that excess compound is removed after mounting the
flanges to the pipe work. Threads of pipe and nipples must be smooth and
free of tears and burrs. Steam clean all piping to remove foreign
substances such as cutting oil or thread chips.
!
WARNING: Shock Hazard. Avoid electrical shock and equipment
damage by disconnecting electrical power to the valve
before proceeding.
!
CAUTION: Equipment damage hazard. For 24V applications,
the ground wire must not be connected to prevent
possible grounding of the 24V transformer secondary.
Observe that the operating voltage is identical to the information on the
product identification label.
Route the electrical connection for the valve solenoid actuators from the
burner sequence control to the standard plug (DIN 43 650) and make the
wiring connections in accordance with Figure 3.
1
3
PE
(
Ground
)
N
(
Common
)
1
3DIN Terminals
Line
Figure 3: Electrical Connection Diagram
Electrical
Connection
(from burner
sequence
control)

GGas Combustion Combination Controls and SystemsGS Series Single-Block Gas Control Valve 5
The internal diameter of the impulse tubes for the combustion air (PA) and
the combustion chamber pressure, (PF) should be 5/32 inch (4.0 mm) (see
Figure 4). Make the connections as short as possible and route to prevent
the entry of condensate into the controller. The installation of a
condensation trap in the connection line from the combustion chamber is
highly recommended. Do not close the connection for PFif not used.
PFPA
Figure 4: Impulse Line Connections
Close the upstream shutoff cock. Connect the test pressure of a maximum
of 1 psi (70 mbar) to inlet pressure connection. Paint the pipe connection
to the valve with a rich soap and water solution. Open the upstream
shutoff cock and if bubbles occur this is an indication of a gas leak. To
stop a leak, tighten joints and pipe connections. Replace the part if the
leak cannot be stopped.
Connection of the
Impulse Lines on
the GS-406_
Checking for
Leakage

6 G Gas Combustion Combination Controls and SystemsGS Series Single-Block Gas Control Valves
Pressure regulator adjustment must be made in conjunction with the gas
appliance. See each version for specific adjustments.
This valve provides manual flow adjustment throughout the full range
from zero to maximum flow.
Flow adjustment is accessible below the metal plate on top of the valve
cover. To adjust this device, loosen the screw nearest to the +/- scale and
swing out the metal plate. Flow adjustment can now be accomplished by
selective positioning of the adjustment screw.
Several hand turns of the setting screw, without undue force, will cover
flow adjustment from almost zero to 100% of the maximum flow for most
specific applications.
The slow opening device is factory adjusted to maximum start gas
position. The valve is factory adjusted to maximum flow.
The adjustment ring is provided with an unsealed locking screw. Loosen
this screw and turn the entire damper assembly. Flow can now be adjusted
from maximum flow down to the desired rate.
!
CAUTION: The minimum flow rate of the valve must not be
adjusted beyond the minimum safety working rate of
the appliance.
For fast open/step adjustment, remove the cap then turn the adjustment
screw counterclockwise until the required step level has been attained.
Loosen the screws of the metal plate on top of the cover to access pressure
adjustment screw, using a screwdriver to adjust to the required value.
To ensure proper control function, the pressure regulator must operate
within its control range. With a selected pressure drop, the flow must
remain within the given limits.
With valve in the open position, the plug screw (see Figure 5) below the
gas outlet can be removed to check the start gas pressure. The scale (PST)
will show the setting (see Figure 6). As these are approximations, a
subsequent fine adjustment may be necessary.
Adjustments
Version GS-_01_
Version GS-_02_
Version GS-_03_
Version GS-405_

GGas Combustion Combination Controls and SystemsGS Series Single-Block Gas Control Valve 7
Figure 5: Plug Screw Position
PST
PG
5-50
2
610
Figure 6: PST Setting
The start gas pressure (PST) remains at the set level until the plug screw is
replaced and tightened. The pressure then rises to the setpoint (PG).
Requirement: PG>PST
Now PGcan be adjusted.
The repeated switching of cycles will permit the observation of the
pressure regulator timing and control performance (see Figure 7). The PG
setting can also be revised.
PG
PST
3 - 12 seconds
Time (s)
PG
Figure 7: Pressure Regulator Timing vs. Control Performance

8 G Gas Combustion Combination Controls and SystemsGS Series Single-Block Gas Control Valves
Start repetitions require an interim pause of approximately 20 seconds for
the evacuation of the pressure chamber.
With test pressure for external leakage applied, adjust pointer on scale (PG)
to white dot within curved ramp (see Figure 6).
For a typical installation, see Figure 8.
M
Gas/Air
Controller
Gas
Line
Manual
Shutoff
Valve
Boiler
Air Line
PGPA PF
PG= Internal Gas Pressure Feedback Line
PA= Air Pressure Feedback Line
PF= Combustion Chamber Pressure Feedback Line
GS Series Combination Control
Pressure
Switch
Filter/
Strainer
Solenoid
Valve Working
With Controller
Figure 8: Typical Application Installation
The ratio (R) of gas outlet pressure (PG) to combustion air pressure (PA) is
adjustable within a range of 0.6:1 to 6:1 (see Figures 9 and 10).
Zero set (Z) can be accomplished by parallel shift of the characteristic
curve from -0.8 to +0.8 inches W.C. (-2 to +2 mbar) (see Figure 9).
When operating the burner in low fire position, the gas/air ratio is adjusted
on scale (Z).
Version GS-406_

GGas Combustion Combination Controls and SystemsGS Series Single-Block Gas Control Valve 9
Z
0
-+
R
1
0,6
23
4
5
6
Figure 9: Zero Setpoint and Gas/Air Ratio Adjustment
Z0.6:1
0.7:1
1:1
2:1
3:1
5:1
6:1
004812 16 20
4
8
12
16
20
PG- PF(Inches W.C.)
PG(Inches W.C.)
PA
(
Inches W.C.
)
PA- PF
(
Inches W.C.
)
Figure 10: Analysis Chart
With burner in maximum load position, the gas/air ratio must be adjusted
on the scale (R) to meet the desired flue gas analysis readings. Then check
the flue gas analyses on low and high settings without manipulating the
adjustments, and thereafter, revise the settings if necessary.
Adjustment of the zero set (Z) and the gas/air ratio (R) can be made
against the marked scales on both sides of the controller module. Scale
divisions are approximate.
The factory settings are:
•zero set: (Z) = 0
•gas/air ratio: (R) = 1:2
Make adjustments in accordance with burner manufacturers’ instructions
and check the outlet pressure at the pressure tap.
Otherwise set the burner to the low fire position, perform a flue gas
analysis, and vary outlet pressure with adjustment on the scale (Z) until the
desired flue gas analysis readings are obtained.

10 G Gas Combustion Combination Controls and SystemsGS Series Single-Block Gas Control Valves
Set the burner to the maximum load and make flue gas analysis. Then
adjust the outlet pressure against the scale (R) until the desired flue gas
analysis readings are obtained.
Check the flue gas analysis readings on the low and high settings without
manipulating adjustments. Thereafter revise settings if necessary.
The outlet pressure PG:
•without combustion chamber pressure PF: PG= R •PA+ Z
•with combustion chamber pressure PF: PG- PF= R •( PA- PF) + Z