Johnson Controls System 350, S350As, S350Cs, S350P, S351A Technical Bulletin

System 350™

S350A Temperature, S351A Humidity,

and S352A Pressure Stage Modules

The S350A, S351A, and S352A Stage Modules are
intended to be used with System 350™ controls. Each
of these stage modules plugs into the respective
control module to add multiple-stage capability. These
stage modules have Single-Pole, Double-Throw
(SPDT) relay output with Light-Emitting Diode (LED)
indication.

As are all System 350 products, the stage modules are
housed in NEMA 1, high-impact thermoplastic
enclosures. The modular design provides easy,
plug-together connections for quick installation and
future expandability.

FANs 930, 125

Product/Technical Bulletin S350

Issue Date 0300

Modular Design

❑

Plug-together Connectors

❑

and 35 mm DIN Rail
Mounting

Selectable Mode of

❑

Operation

Adjustable Differential

❑

Adjustable Offset

❑

Figure 1: System 350 Stage Module

Features and Benefits

Permits system to be configured to
equipment, with convenient, future expansion
made easy

Eliminates wiring between modules and
reduces installation costs

Provides independent relay energization,
either above or below setpoint, for
cooling/heating (S350A),
dehumidification/humidification (S351A), or
direct acting/reverse acting (S352A)

Enables user to match the range of
temperature, humidity, or pressure stage
modules to specific application requirements

Allows multiple stage sequencing of 1-30F°
(0.5-17C°) (S350A), 2-30% RH (S351A), or
2-50 psi (S352AA-2)

© 2000 Johnson Controls, Inc.

Part No. 24-7664-1, Rev. D www.johnsoncontrols.com
Code No. LIT-930080

1

pplication

A

The S350A, S351A, and S352A Stage Modules
receive power, setpoint, and sensor input from the
respective System 350 control modules. When
connected, the individual modules act as a multistage
control system.

The maximum number of stages that can be used in a
system varies with the control module type
(temperature, humidity, or pressure) and stage module
design.

Refer to Table 1 or Table 2 to determine the maximum
number of stages that may be used with each control
module. When mixing stage module designs, always
use the lower number.

Note: When using an external transformer, the

Y65 Series or other 40 VA Class 2
transformers are recommended.

Table 1: Maximum Number of Add-on
Modules when Powered by a Y350R
Power Module

Control
Module

A350A
A350B
A350E

A350P

A350R
A350S

W351A

W351P

P352AB

P352PN

Stage

Module

No. Model

Numbers

9

S350As or S350Cs

6

S350As or S350Cs
with 1 S350P
S350As or S350Cs

4

with 2 S350Ps

42S350As or S350Cs

S350As or S350Cs
with 1 S350P

9

S350As or S350Cs

6

S350As or S350Cs
with 1 S350P
S350As or S350Cs

4

with 2 S350Ps

5 S351As 1 D351

4 S351As 1 D351

5 S352As 1 D352A

4 S352As 1 D352A

Display
Module

No. Model

Number

1 D350

1 D350

2 D350s

Table 2: Maximum Number of Add-on
Modules when Powered by an External
Transformer

Control
Module

Stage

Module

No. Model

Numbers

A350A
A350B
A350E

A350P

A350R
A350S

W351A

W351P

P352AB

P352PN

9

S350As or S350Cs

8

S350As or S350Cs
with 1 S350P
S350As or S350Cs

7

with 2 S350Ps

9

S350As or S350Cs

8

S350As or S350Cs
with 1 S350P
S350As or S350Cs

7

with 2 S350Ps

9

S350As or S350Cs

8

S350As or S350Cs
with 1 S350P
S350As or S350Cs

7

with 2 S350Ps

9 S351As 1 D351

9 S351As 1 D351

9 S352As 1 D352A

9 S352As 1 D352A

Notes: This bulletin only refers to the S350A, S351A,

and S352A Stage Modules.

For information on the S350C refer to the

System 350

TM

S350C Temperature Slave
Stage Module Product/Technical Bulletin
(LIT-930084).

For information on the S350P refer to the

System 350

TM

S350P Proportional Plus
Integral Temperature Stage Module
Product/Technical Bulletin (LIT-930086).

For information on the D350, D351 and D352
refer to the

System 350

TM

D350 Display
Modules Product/Technical Bulletin
(LIT-930070)

.

Display
Module

No. Model

Number

1 D350

1 D350

2 D350s

2

S350A Temperature, S351A Humidity, and S352A Pressure Stage Modules Product/Technical Bulletin

O

peration

The S350A, S351A, and S352A Stage Modules
provide SPDT relay output. A front panel LED lights to
indicate when the relay is energized.

IMPORTANT: The System 350 Stage Modules

are intended to control
equipment under normal
operating conditions. Where
failure or malfunction of the
System 350 Stage Modules
could lead to an abnormal
operating condition that could
cause personal injury or damage
to the equipment or other
property, other devices (limit or
safety controls) or systems
(alarm or supervisory systems)
intended to warn of or protect
against failure or malfunction of
the System 350 Stage Modules
must be incorporated into and
maintained as part of the control
system.

Offset Adjustment

The offset adjustment determines the amount of offset
from the control module setpoint at which the stage
module relay de-energizes.

With the jumpers positioned vertically, the stage
module is set for Heating (S350A), Humidification
(S351A), or Reverse Acting (RA) (S352A) operation. In
this mode, the relay and LED indicator de-energize
when the sensed temperature, humidity, or pressure
rises to the setpoint

minus

offset value.

Note: The S350A, S351A, and S352A Stage

Modules are configured with the jumpers in
the horizontal position at the factory.

Refer to Figures 6, 7, and 8 for examples of S350A,
S351A, and S352A applications.

imensions

D

Mounting Slots

For No. 6 Screws

1-1/2

(40)

1/8 (4)

2-15/16

(75)

7/16

(11)

DIN Rail
Mount

5 (127)

1-3/16

(31)

ON

JOHNSON

CONTROLS

CONTROLS

2-3/8

(61)

S350

O

O

Differential Adjustment

Differential is defined as the difference in degrees,
% RH, or psi between energization and
de-energization of the stage module’s relay.

Operation Mode Selection

The S350A, S351A, and S352A utilize jumpers (at
jumper terminal J2) to select the operation mode. (See

Adjustments

With the jumpers positioned horizontally, the stage
module is set for Cooling (S350A), Dehumidification
(S351A), or Direct Acting (DA) (S352A) operation. In
this mode the relay and LED indicator de-energize
when the sensed temperature, humidity, or pressure
drops to the setpoint

section and Figures 3, 4, and 5.)

plus

offset value.

2-3/8

(61)

7/8 (22)

Conduit

Hole

7/8 (22)

Figure 2: System 350 Stage Module

Dimensions, in. (mm)

ounting

M

Each System 350 Stage Module is housed in a
compact NEMA 1 plastic enclosure designed for
standard 35 mm DIN rail mounting. Four key-slot
mounting holes on the back of the control case are
provided for surface mounting. (See Figure 2.) The
modules are not position sensitive, but should be
mounted for convenient access to wiring and
adjustments.

Note: When mounting any System 350 module to

rigid conduit, attach the hub to the conduit
before securing the hub to the control
enclosure.

S350A Temperature, S351A Humidity, and S352A Pressure Stage Modules Product/Technical Bulletin

3

djustments

A

Refer to the following steps for adjusting stage module
settings. (See Figures 3, 4, and 5.)

!

WARNING:

Risk of Electrical Shock.

Disconnect power supply to
avoid possible electrical shock or
equipment damage. More than
one disconnect may be required
to completely de-energize
equipment.

1. Ensure all power to system is off.

Each stage module may be receiving separate
power sources. Make sure all power sources to
each stage module are off.

2. Remove the stage module cover by loosening the
four captive cover screws.

Set the mode of operation

3.

by positioning the
jumpers (at jumper terminal J2) for Cooling,
Dehumidification, or Direct Acting mode. Position
the jumpers vertically for Heating, Humidification,
or Reverse Acting mode.

Note: The S350A, S351A, and S352A Stage

Modules are configured with the jumpers in
the horizontal position at the factory.

Adjust the differential

4.

using the potentiometer
marked DIFF to the desired setting (the difference
in degrees, % RH, or psi between energization
and de-energization of the stage module’s relay).

Adjust the offset

5.

using the potentiometer marked
OFFSET to the number of degrees, % RH, or psi
from the System 350 control’s setpoint at which
the stage relay de-energizes (above setpoint with
Cooling, Dehumidification, or Direct Acting mode
selected, or below setpoint with Heating,
Humidification, or Reverse Acting mode selected).

6. Replace the cover on the stage module and fasten
in place with screws.

7. Restore power to system.

Potentiometer

Module

Connector

Relay Energized

LED Indicator

Cover Screw

1 of 4

Offset

N.C.

Relay

Relay

COM

Output

Differential

Potentiometer

Module

Connector

Jumper

Position at J2

Heating

Cooling

N.O.

Terminals

Figure 3: Interior View of S350A Stage Module

Offset

Potentiometer

Module

Connector

Relay Energized

LED Indicator

Cover Screw

1 of 4

N.C.

Relay

Relay

COM

Output

Differential

Potentiometer

Module

Connector

Jumper

Position at J2

Humidification

Dehumidification

N.O.

Terminals

Figure 4: Interior View of S351A Stage Module

Offset

Potentiometer

Module

Connector

Relay Energized

LED Indicator

Cover Screw

1 of 4

Relay

Differential

Potentiometer

Module

Connector

Jumper

Position at J2

Reverse

Acting
Direct

Acting

4

S350A Temperature, S351A Humidity, and S352A Pressure Stage Modules Product/Technical Bulletin

N.C.

Relay

COM

Output

N.O.

Terminals

Figure 5: Interior View of S352A Stage Module

Higher

Temperature

Setpoi nt

Temperature

Lower

Temperature

ON
Differential

ON

Differential

OFF

OFFSET

OFF

OFF

ON = Energized

OFF = De-energized

A350

Stage 1

S350A

Stage 2

Cooling

OFFSET

Differential

S350A

Stage 3

ON

OFFSET

OFF

Differential

S350A

Stage 4

Heating

ON

S350A

Stage 5

OFFSET

OFF

Differential

ON

Higher

Pressure

Setpoint

Pressure

Lower

Pressure

Differential

ON

Differential

OFF

OFFSET

OFF

ON = Energized

OFF = De-energized

P352AB

Stage 1

S352A

Stage 2

Direct

ON

OFFSET
OFF

S352A

Stage 3

Reverse

Differential

ON

S352A

Stage 4

OFFSET

OFF

Differential

ON

Figure 6: Example of a Heating/Cooling

Application Using One A350 and Four S350As

Higher

Humidity

Setpoi nt
Relative

Humidity

Lower

Humidity

ON
Differential

OFF

ON = Energized

OFF = De-energized

W351

Stage 1

Dehumidify

OFF

OFFSET

S351

Stage 2

ON

Differential

OFFSET

OFF

S351

Stage 3

Humidify

Differential

ON

OFFSET

OFF

S351

Stage 4

Differential

ON

Figure 7: Example of a

Humidification/Dehumidification Application

Using One W351 and Three S351As

Figure 8: Example of a Reverse Acting/Direct

Acting Application Using One P352AB

and Three S352As

iring

W

Refer to the following guidelines and wiring diagrams
for proper wiring and terminal designations (See
Figures 9, 10, and 11.)

Note: For information on connecting to an external

transformer refer to the applicable control
bulletin.

!

WARNING:

Risk of Electrical Shock.

Disconnect power to avoid
possible electrical shock or
equipment damage. More than
one disconnect may be required
to completely de-energize
equipment.

IMPORTANT: Make all wiring connections in

accordance with the National
Electrical Code and all local
regulations. Use copper
conductors only. Do not exceed
the control’s electrical ratings.

S350A Temperature, S351A Humidity, and S352A Pressure Stage Modules Product/Technical Bulletin

The stage modules plug into the control and other
add-on modules via 5-pin connectors located on either
side of each module. Wiring is made at the Normally
Open (N.O.)/Normally Closed (N.C.) relay terminal
strip. (See Figures 3, 4, and 5.)

5

Wire

Ter min al

Block

24V

COM

VDC
SEN

120 VAC

SEN

Shield (Connect

only to COM on A350)

A350

COM

Y350R

Sensor

Isolate and tape. (Do not ground

this end of cable shield.)

S350A D350

S350A S350A

Load

Load

Load

Load

Figure 9: Typical Multistage Temperature Control System Using 120 VAC Power Supply

Transmitter

Wire

Ter min al

Block

24V

COM

VDC
SEN

120 VAC

SEN

only to COM on W351)

W351 Y350R

VDC

Shield (Connect

Load Load

COM

S351A D351S351A S351A

Isolate and tape. (Do not ground

this end of cable shield.)

Load

Load

Figure 10: Typical Multistage Humidity Control System Using 120 VAC Power Supply

SEN

only to COM on P352AB)

P352AB

VDC

Shield (Connect

Y350R S352A S352A

COM

Wiring Harness

Isolat e and tape. (Do not ground

this end of cable shield.)

P399 Transducer

D352AS352A

Wire

Ter min al

Block

24V

COM

VDC

SEN

120 VAC

Figure 11: Typical Multistage Pressure Control System Using 120 VAC Power Supply

6

S350A Temperature, S351A Humidity, and S352A Pressure Stage Modules Product/Technical Bulletin

Load

Load

Load

Load

heckout Procedure

C

Before applying power, make sure installation and
wiring connections are according to job specifications.
After necessary adjustments and electrical
connections have been made, put the system in
operation and observe at least three complete
operating cycles before leaving the installation.

roubleshooting

T

If the control system does not function properly, first
verify that the control, power, and display modules are
all operating correctly (refer to the respective
literature). Then inspect the stage modules for proper
operation.

Check that the proper operating mode
(Cooling/Heating, Dehumidification/Humidification, or
Direct Acting/Reverse Acting) has been selected on
each stage module. (See

Adjustments

section and
Figures 3, 4, and 5.) Then perform the following
procedures to determine the problem.

1. Verify the system has power.

2. Note the offset and differential settings on the

stage module.

3. Turn the setpoint dial on the control module to

minimum.

4. Increase the setpoint by slowly adjusting the

setpoint dial until the stage relay LEDs turn On
and Off as shown in Tables 3, 4, or 5.

Table 3: S350A Relay Troubleshooting

Operation

LED

Mode

Cooling

Cooling

Heating

Heating

*(Ts) = sensed temperature

On Closed

Off Open (Ts) – offset

On Closed

Off Open (Ts) + offset

N.O.
Relay
Status

Setpoint Dial
Setting

(Ts)* - offset

-

differential

(Ts) + offset

+

differential

Table 4: S351A Relay Troubleshooting

Operation
Mode

LED N.O.

Relay
Status

Dehumidify

Dehumidify

Humidify

Humidify

*(RHT) = actual relative humidity at transducer

On Closed (RHT)* -offset

Off Open (RH

On Closed (RH

Off Open (RHT) + offset

Setpoint Dial
Setting

-

differential

) - offset

T

) + offset

T

+

differential

Table 5: S352A Relay Troubleshooting

Operation
Mode

LED N.O.

Relay
Status

Direct

Direct

Reverse

Reverse

*(psiT) = actual pressure at transducer

On Closed (psiT)*- offset

Off Open (psi

On Closed (psi

Off Open (psiT) + offset

5. If the relays do not perform as indicated in
Tables 3, 4, or 5, adjust the stage module’s
differential and offset potentiometers to minimum
and repeat Steps 1 through 3.

6. If the relays still do not turn on and off, replace the
defective stage modules.

Note: There is the unlikely possibility that a defect in

one stage module could cause defective
symptoms in all modules. Plug each stage into
the control individually and check the
performance of each as explained above.

epairs and Replacement

R

Do not make field repairs or perform calibration.
Sensors and replacement controls are available
through your local Johnson Controls representative.

Setpoint Dial
Setting

differential

) - offset

T

) + offset

T

differential

-

+

S350A Temperature, S351A Humidity, and S352A Pressure Stage Modules Product/Technical Bulletin

7

rdering Information

O

Table 6: Ordering Information

Item Product Code

Description

Number

S350A Temperature Stage
Module

S351A Humidity Stage Module

S352A Pressure Stage Module

pecifications

S

Product

Input Voltage

Power Consumption

Output Relay Electrical

Ratings

Differential Adjustment

Range

Offset Range

Ambient Temperature

Ambient Humidity

Material

Mounting

Agency Listing

The performance specifications are nominal and conform to acceptable industry standards. For application at conditions beyond these
specifications, consult Johnson Controls/Penn Application Engineering at [phone]. Johnson Controls, Inc. shall not be liable for
damages resulting from misapplication or misuse of its products.

S350AA-1C Temperature Stage Module with Fahrenheit Scale

S350AB-1C Temperature Stage Module with Celsius Scale

S351AA-1C Humidity Stage Module with percent RH Scale

S352AA-2C Pressure Stage Module with psi Scale

S350AA: Temperature Stage Module with Fahrenheit Scale
S350AB: Temperature Stage Module with Celsius Scale
S351AA: Humidity Stage Module with Percent RH Scale
S352AA-2: Pressure Stage Module with psi Scale

S350AA: Provided by the A350
S351AB: Provided by the W351
S352AA-2: Provided by the P352AB

1.0 VA maximun

SPDT Enclosed Relays
10 Ampere Non-inductive, 125 VA Pilot Duty, 24/240 VAC
1/2 hp 120/240 VAC

S350AA: 1 to 30F°
S350AB: 0.5 to 17C°
S351AA: 2 to 10% RH
S352AA-2: 2 to 50 psi

S350AA: 1 to 30F°
S350AB: 0.6 to 16.7C°
S351AA: 2 to 30% RH
S352AA-2: 2 to 50 psi

Operating: -30 to 150°F (-34 to 66°C)
Shipping: -40 to 185°F (-40 to 85°C)

0 to 95% RH (Non-condensing)

Case, Cover: NEMA 1 High Impact Thermoplastic

Wall or DIN Rail

UL Listed, CCN XAPX, File E27734
UL Listed for Canada, CCN XAPX7, File E27734

Controls Group

507 E. Michigan Street
P.O. Box 423 Printed in U.S.A.
Milwaukee, WI 53201 www.johnsoncontrols.com

8

S350A Temperature, S351A Humidity, and S352A Pressure Stage Modules Product/Technical Bulletin