SCX 920
Installation Guide
Andover Controls Corporation i
Downloaded from - http://www.guardianalarms.net
Version D
Reproduction or d istribution forbidden.
Copyright 1997 by Andover Cont rols.
Subject to change without notice.
Order No. 30-3001-170
Copyright
1997
Andover Controls Corporation
300 Brickstone Square
Andover, Massachusetts 01810
All Rights Reserved.
Published by the Engineering Departm ent at Andover Controls Corporation.
IMPORTANT NOTICE
This product is subject to change without notice. This document does not constitute any warranty, express or implied. Andover Controls Corpor ation reserves the right to alte r cap ab ilities, performanc e, and pres e ntation of this
product at any time.
ii SCX 920 Installation Guide
Preface
The SCX 920 Installation Guide presents instructions for installing the
SCX 920 on an Infinet network. It first presents site prep aration infor-
mation and then step-by -ste p ins talla tion instructions.
Andover Controls Corporation iii
iv SCX 920 Installation Guide
Contents
Setting Up the SCX 920 Controller and Infinet
Site/System Setup Requirements .............................................................2
Controller Dimensions and Weight ...............................................3
Power Requirements ......................................................................3
Cable Limitations . ..... .... ... ..... .. ..... .... ... ...... . ..... .. ..... .... ... ...... . ....... .. .3
Lightning Protection ......................................................................4
Building Ground Requirements ..................................................... 4
Inspecting the Ground ....................................................................5
Environmental Requirem en ts ....... ......... .......... ......... ................... ..5
Output Equipment Requirements ..................................................6
Form C Outputs .............................................................................6
Analog Outputs—Voltage .............................................................6
Analog Outputs—Current ..............................................................6
Input Circuit Specifications ...........................................................7
Special Factors for Thermistors .....................................................7
Laying Out the Site Setup ..............................................................9
Installing the SCX 920........................................................................... 10
Parts Requir ed ................ .......... ................... ......... .......... ..............10
Mounting ............. ................... ......... ......... ................... .......... .......10
Disabling the Manual Overrides ..................................................12
Connecting the Battery ................................................................16
Connecting the AC Power ...........................................................16
Selecting the AC Input Voltage ... .......................... ......................1 7
Andover Controls Corporation v
Wiring the Infinet to the SCX 920 ...............................................18
Wiring the Infinet to the Infinity CX 9000 ............... ...................19
Setting the Input Reference Resistor Switches ............................19
Wiring the Inputs .........................................................................19
Wiring the Outputs ......................................................................2 3
Wiring Tristate Outputs ...............................................................23
Wiring Analog Outputs—Voltage ...............................................2 4
Wiring Analog Outputs—Current ...............................................25
Wiring Form C Outputs ...............................................................25
Setting the Override Switches .....................................................26
Connecting Modules to the Expansion Port ................................27
Powering Up the SCX 920 ....................................................... ..............28
Reset Button ............ .......... ................... ......... .......... .................. ...29
Adjusting the LCD View Angle ..................................................29
Completing the Installation ..........................................................30
Connecting the Andover Controls Service Tool .................. ....... .3 0
Adjusting Analog Override Values .............................................30
vi SCX 920 Installation Guide
Figures
Figure 1. The Front Cover of the SCX 920 .......................... ....... ....... .1 1
Figure 2. Locations of Screw Holes, Other Openings in Cabinet .......13
Figure 3. The Printed Circuit Board of the SCX 920 ........... ....... ....... .1 5
Figure 4. Metal Plate and Screw for Power Supply Wire ...................17
Figure 5. Infinet Cable Wiring ............................................................18
Figure 6. Wiring Diagram for Thermis tor Input ............ ....... .. ..... .... ... .2 1
Figure 7. Wiring Diagram for Counter or Digital Input...................... 21
Figure 8. Wiring Diagram for Voltage Input .......................................22
Figure 9. Wiring Diagram for Curren t Input ...................................... .22
Figure 10. Wiring Diagram for Tristate Outputs ...................................24
Figure 11. Wiring Diagram for Voltage Outputs ..................................25
Figure 12. Wiring Diagram for Current Outputs ...................................25
Figure 13. Wiring Diagram for Form C Outputs ...................................26
Figure 14. Five Positions on Odd Numbered Override Switch............. 27
Andover Controls Corporation vii
Tables
Table 1. Wire Gauges and Corresponding Maximum Runs
º
for Sensing Temperatures Up to 70
Table 2. Wire Gauges and Corresponding Maximum Runs
for Sensing Temperatures Up to 100º F .................................8
Table 3. Wire Gauges and Corresponding Maximum Runs
for Sensing Temperatures Up to 150º F .................................9
Table 4. Connecting Jumpers for AC Input Voltages .. ....... ....... ....... .1 7
Table 5. Corresponding Override Swit ch Settings
for Different Outputs Types .................................................2 7
F ...................................8
viii SCX 920 Installation Guide
Setting Up the SCX 920
Controller and Infinet
This manual covers the following:
• Site/System Setup Requirement s
• Installing the SCX 920
• Powering Up the SCX 920
Warranty Registration
Your warranty is effective for 18 months starting on the date the system
is shipped.
Warning
All wiring and installations must comply with local, state, and national
electrical codes.
SCX 920 Installation Guide 1
Hardware Instal lation
Site/System Setup Requirements
Before you proceed to install the system, you should map out where you
plan to install each controller, terminal/workstation, and modem. When
planning the sites, be aware of any electrical interference that may occur. You also need to be aware of cabinet dimensions, power
requirements, cable limitations, an d environm ental requir e ments .
Note
This equipment has been tested and found to comply with the limits for
a Class A digital device, pursuant to Part 15 of the FCC Rules. These
limits are designed to provide reasonable protection against harmful
interference when the equipment is operated in a commercial
environment. This equipment generates, uses, and can radiate radio
frequency energy and, if not installed and used in accordance with the
instructions in this manual, may cause harmful interference to radio
communications. Operation of this equipment in a residential area is
likely to cause harmful interference in which case the user will be
required to correct the interference at his own expense.
Note
This digital apparatus does not exceed the Class A limits for radio noise
emissions from digital apparatus set out in the Radio Interference
Regulations of the Canadian Department of Communications.
Avis
Le présent appareil numérique n’émet pas de bruits radioélectriq ues
dépassant les limites applicables aux appareils numériques de la class A
prescrites dans le Règlement sur le brouillage radioélectrique édicté par
le ministère des Communications du Canada.
2 SCX 920 Installation Guide
Hardware Installation
Controller Dimensions and Weight
Each SCX 920 is 14.7 × 10.7 × 2.75 in. and weighs 8 lbs.
Power Requirements
Caution
The SCX 920 should receive power from its own independent,
unswitched circuit.
You can select a power supply voltage of 24 V, 120 V, or 240 V. You
receive it set to 115 V. Instructions for selecting the power supply you
want are included with the installation.
Voltages you can select are as follows (each uses a 3 A slow blow fuse):
• 24 VAC +/– 20% 50/60 Hz (for smoke control applications
24 VAC +10/– 15% 60 Hz)
• 120 VAC +/– 20% 50/60 Hz (for smoke control applications
120 VAC +10/– 15% 60 Hz)
• 240 VAC +/– 20% 50/60 Hz (for smoke control applications
240 VAC +10/– 15% 60 Hz)
The SCX 920 consumes 32 VA of power.
Cabl e Limitations
The maximum cable length for all buses is 4,000 ft at 19,200 baud (up
to 32 Infinet controllers). You can extend buses beyond 4,000 ft or put
more than 32 Infinet contr ollers on less than 4,00 0 ft by using the
InfiLink 200 amplification module.
Note
You mu s t use s hie ld ed ca bl es f o r Infinet to ensure compliance with the
Class A FCC limits and to provide reliable communications.
SCX 920 Installation Guide 3
Cables that form Infinet are 24-gauge, single-t wis ted-pair , tin ned,
shielded copper wire.Use the following cables1 or their equivalents:
• Brand Rex # H 9002 (single-pair)
• Anixter # 9J2401021 (single-pair plenum cable)
The cable should have a nominal impedance of 100 Ohms and a nominal
velocity of propagation of 78%. Capacitance of Infinet cable should be
nominal, below 12.5 pF/ft between conductors and below 22 pF/ft between the conduc t or connected to grou nd and the ne xt conductor.
Lightning Protection
Lightning Arresters are required at each point where a bus cable enters
or exits a building. Use the following arrester:
Two pair gas tube arrester, Andover Controls # 01-2100-299
Hardware Instal lation
Building Ground Requirements
Warning
Be sure that all Infi nity products from Ando ver Controls Corporation
are grounded to true earth ground. This kind of ground protects the
equipment from transients and other power surges in the area.
We cannot guarantee that the controller system will operate as
documented unless you properly grou nd all control lers .
Warning
Be sure to have your grounds inspected before you begin the
installation process to be sure your municipality follows the National
Electrical Code. M a ny muni ci palitie s do not an d often have
substandard electrical grounds.
An example of a substandard ground is a galvanized steel cold water
pipe. As the pipe corrodes, it does not act as a true ground. The corro-
1. You can also use any cables you may already have in place for ACNET or LBUS.
4 SCX 920 Installation Guide
Hardware Installation
sion acts as an insulator, raising the potential of the pipe with respect to
the ground.
When lightning strikes in the area of the ins talla tion, it drastically
changes the potential of the earth. Since properly grounded Andover
Controls units respond to changes in potential more rapidly than poorly
grounded electrical systems, a poorly grounded buildi ng tries to reach
ground through the Andover Controls system. The surge of current can
destroy electronic components on the controller board.
Surges of much lower potential than lightning also impact the reliability
of Andover Controls equipment.
Inspecting the Ground
You can check your ground as follows:
1. Check your ground by first inspecting the building power
distribution panel for earth ground termination. If the ground
termination is any of the following, it is not adequate and must be
corrected:
• Does not exist.
• Is connected to a corroded or galvanized pipe.
• Is connected using a small gauge wire (less than 14 AWG).
2. Be sure your Andover Controls cabinet is connected to the ground
with a copper conductor that terminates at the distribution panel.
Environmental Requirements
The SCX 920 operates in rooms with temperatures ranging from 32 to
120°F and with humidity up to 85%, non-condensing.
The controller must be in an Underwriter Laboratories approved
enclosure.
SCX 920 Installation Guide 5
Output Equipment Requirements
The eight outputs on the SCX 920 are universal and can be wired to pro-
vide direct digital control for virtually all electronic devices, pneumatic
analog devices, and bi-directional motors and actuators. They can be
wired so that you have Form C, analog (voltage or current), or tristate
outputs, or a combination of them.
Analog outputs can be a variable current (0 to 20 mA) or a variable voltage (0 to 20 V). In addition to standard ON/OFF for digital outputs and
(and ON/OFF/–ON for trist ate), both digital and tristate outputs have
pulse width modulation (PWM). PWM allows you to modulate valves
and dampers to 0.1 sec resolution.
All outputs are programmable. Eight override rotary switches let you
either manually control each output or set i t t o AUTO so the controller
Hardware Instal lation
can control it.
Form C Outputs
The Form C relay of each output is rated for 5 A at 50 VAC.
Analog Outputs—Vo lta ge
The voltage output provides 5 mA maximum output over the range of 0
to 20 VDC. The input impedance of the device being controlled can be
no less than 4000 Ω.
Analog Outputs—Current
The current output provides a 0 to 20 mA control signal. The input
impedance of the device being controlled can be no greater than 750 Ω.
The circuitry that produces the 0 to 20 mA signal acts as a “current
sourcing device.” It sources the current to ground.
6 SCX 920 Installation Guide
Hardware Installation
Input Circuit Specifications
Caution
Andover Controls inputs are designed to be used with two-wire devices
and do not provide sufficient power to operate sensors or transducers
requiring an external power supply.
The following specifications apply to SCX 920 inputs:
• Voltage Range—0 to 10.000 V
• Resolution—0.0025 V
• Accuracy—+/–0.005 V
• Maximum Pulse Frequency—5 Hz at a duty cycle of 50% and a
minimum pulse width of 100 ms
• Input Impedance—30.1 KΩ referenced to 10. 000 V
or 10 MΩ referenced to ground with the input reference resistor
switch set to OUT
• Filtering—Corner Frequency at 16 Hz –20 db/decade
• Over-Voltage Protection—120 VAC RMS or 120 VDC indefinitely
on any single channel; +/–1500 V transient for 50 µs on all channels
• Calibration—Per manent (f actory)
Special Factors for Thermistors
To keep thermistor errors minimal, lay out your site so you can limit the
length of wire runs to the maximum for the gauge wire you select.
SCX 920 Installation Guide 7
Hardware Instal lation
Table 1 shows the maximum runs for wires of various gauges to keep
errors within .5°F, .25°F, and .10°F when sensing temperatures up to
70°F.
Table 1. Wire Gauges and Corresponding Max imum Runs
for Se nsing Temperatures Up to 70
Gauge
#14 26,700 ft 13,300 ft 5300 ft
#16 16,800 ft 8400 ft 3300 ft
#18 10,500 ft 5200 ft 2100 ft
#20 6600 ft 3300 ft 1300 ft
#22 4100 ft 2000 ft 800 ft
1
/
°
2
F Error
1
/
F Error1/
°
4
°
F
10
F Error
°
Table 2 shows the maximum runs for wires of various gauges to keep
errors minimal when sensing temperatures up to 100°F.
Table 2. Wire Gauges and Corresponding Max imum Runs
°
for Se nsing Temperatures Up to 100
Gauge
#14 12,700 ft 6300 ft 2500 ft
1
/
°
2
F Error
1
/
F Error1/
°
4
F
F Error
°
10
#16 7900 ft 3900 ft 1500 ft
#18 5000 ft 2500 ft 1000 ft
#20 3100 ft 1500 ft 600 ft
#22 1900 ft 900 ft 300 ft
8 SCX 920 Installation Guide
Hardware Installation
Table 3 shows the maximum runs for wires of various gauges to keep
errors minimal when sensing temperatures up to 150°F.
Table 3. Wire Gauges and Corresponding Max imum Runs
for Se nsing Temperatures Up to 150
Gauge
#14 4100 ft 2000 ft 800 ft
#16 2600 ft 1300 ft 500 ft
#18 1600 ft 800 ft 300 ft
#20 1000 ft 500 ft 200 ft
#22 650 ft 300 ft 130 ft
1
/
°
2
F Error
1
/
°
4
Laying Out the Site Setup
You may want to draw a map of where you plan to put each controller
and store it in a notebook.
Find the tag attached to each controller that gives the number of the controller. Bef ore you remove any tags, be sure the tag has all of the
following information on it:
F Error1/
F
°
F Error
°
10
• Location of the controller.
• Serial number.
• Model name and number.
• Communications port the Infinet connects to on Infinity CX 9000.
Then collect the tags. You will need to know where your controll ers are
located when you later assign a name to each controller and each input
and output.
SCX 920 Installation Guide 9
Installing the SCX 920
Parts Required
To install a single controller you start with the following parts:
• SCX 920 Controller
• AC Power Cable
• Input and Output Wires
• Infinet Cable (twisted pair)
• InfiLink 200s as Hubs, Repeaters, or Cable Switching Boxes
Mounting
Hardware Instal lation
Caution
You must encase the SCX 920 in a UL approved cabinet to keep its
Open Class rating.
1. Before you begin, look at the front of the SCX 920 cover.
Figure 1 shows the front of the SCX 920.
2. The front cover of the SCX 920 has two Phillips head quarter turn
fasteners aligned down the center, one above the middle and one at
the bottom. Remove those fas ten ers, holding the cabinet firm so it
does not fall.
3. Remove the cover and place it to one side.
4. If you want to disable the manual overrides, proceed to the next
section and return here when you are finished. Otherwise, continue
with the next step.
10 SCX 920 Installation Guide
Hardware Installation
Figure 1. The Front Cover of the SCX 920
1/4 Turn Fastener
123
5
4
6
789
ON OFF – ON
+/–
0
1
SCX 920
2
CPU
3
4
5
OVERRIDE
TD
RD
SHIFT
LOCK
BACK
SPACE
CANCEL
ENTER
6
EXTERNAL
+24V
7
8
1/4 Turn Fastener
SCX 920 Installation Guide 11
Note that the LCD screen and keypad are optional.
Caution
Never drill holes in the SCX 920 cover or boards. A metal shaving
could easily short circuit the electronics.
5. Screw the SCX 920 to the wall using standard No. 8 screws in the
pre-cut holes in the fou r co rners of the ba se plate .
Figure 2 shows the location of the corner screw holes and
measurements to other all openings in the cabinet.
Disabling the Manual Overrides
Hardware Instal lation
Caution
Be sure power is off during this process, or controller will malfunction.
Before you begin these instructions remove the front cover as described
under Mounting, the previous section .
On top of the printed circuit board is an inner plastic housing connected
by a single screw in the back and six snap latches, one on the top and
bottom and two on either side.
12 SCX 920 Installation Guide
Hardware Installation
Figure 2. Locations of Screw Holes, Other Openings in Cabinet
10.68
14.68
.36
13.96
12.93
11.24
.36
8.64
1.36
9.96
X X
AC
INPUT
GND
NEU
HOT
X X X X
X
X
X
X X
X X
X X
xx
LCD VIEW ANGLE
USE COPPER
CONDUCTORS ONLY
X X
AC INPUT VOLTAGE SELECTION
24V
From
From
To
E1
E1
E3 E4
X X
E2 E5 E2 E2 E7
TP10
TP10
E6 E6 E4
F19, 3A, 250V
SLOW BLOW
115V
To
E7
TP10
SCX 900
+
3.6 V
-
RESET
F1
1/8 A
XX
INPUTS
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
F14
2 A
X
X
X
X
X
X
X
X
X
x
X
x
x
X
x
X
x
X
x
x
X
x
X
x
X
x
INFINET
X
1
X
2
X
3
X
4
X
5
X
6
X
7
X
8
X
IN
9
X
x
10
x
X
11
x
X
x
12
X
x
13
X
x
14
x
X
15
x
X
x
16
X
x
IN
XX
X
RET
INPUT
1
REFERENCE
RESISTOR
2
RET
3
4
RET
5
6
RET
OUT
7
8
RET
INPUT
9
REFERENCE
10
RESISTOR
RET
11
12
RET
13
14
RET
OUT
15
16
+
–
SHLD
SERVICE
PORT
From
X
EPROM
230V
To
----
X
x
x
x
x
x
x
x
x
X
X
x
ADJ
- On
x
X
X
Off
Auto
Off
ADJ
x
Off
Auto
Off
ADJ
Off
x
Auto
Off
ADJ
x
Off
Auto
Off
ADJ
x
Off
Auto
Off
ADJ
x
Off
Auto
Off
ADJ
x
Off
Auto
Off
ADJ
x
Auto
Off
EXPANSION
PORT
x
1
+On
x
- On
+On
-On
+On
- On
+On
-On
+On
- On
+On
-On
+On
+On
Form C
Tristate
x
2
x
STATUS
x
3
4
5
6
7
8
x
x
x
x
x
x
x
OVERRIDE
x
x
Form C
Tristate
x
CPU
TD
RD
+ 24 V
External
x
x
x
x
x
x
1
x
2
3
1/8 A
4
5
1/8 A
6
7
1/8 A
8
4.22
NC
X
C
X
NO
X
I
X
X
V
X
GND
X
GND
X
I
X
V
X
NC
X
C
X
NO
NC
X
C
X
NO
X
I
X
V
X
X
GND
X
GND
X
I
X
V
X
NC
X
C
X
NO
NC
X
C
X
NO
X
I
X
X
V
X
GND
X
GND
X
I
X
V
X
NC
X
C
X
NO
NC
X
C
X
NO
X
I
X
V
X
X
GND
X
I
X
V
X
NC
X
C
X
NO
X
X
6.82
9.42
12.02
SCX 920 Installation Guide 13
Hardware Instal lation
Figure 3 shows the locations of the snap latches. Note the parts of the
controller labeled here. You may want to refer to this figure for
assistance in locating parts during the installation process.
1. Turn over the SCX 920 and remove the screw in the center of the
board.
2. Turn the controller face up and lift out the snap latches around the
edges of the plastic housing to remove it from the printed circuit
board beneath it.
3. Find the slide switches to the left of the rotary override switches and
set the slide switches to the down position to disable the overrides.
Figure 3 shows the locations of the slide switches and rotary
override switches.
Now the output is under program control only. The manual control
option has been disabled.
4. Look inside the plastic housing. You’ll see two cables with pins on
the end.
Figure 3 shows the locations of the connections for these cables.
5. Plug in the cables to reconnect the LCD screen and keypad. Be
careful not to bend the pins.
6. Snap the inner plastic housing back on.
7. Turn the controller over and replace the center screw in the back.
8. Return to step 5 under Mounting.
14 SCX 920 Installation Guide
Hardware Installation
Figure 3. The Printed Circuit Board of the SCX 920
Snap Latch
X
AC
INPUT
GND
X
X
NEU
X
HOT
xx
X
INPUTS
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X X X X
X X
X X
SCX
RET
INPUT
1
REFERENCE
RESISTOR
2
RET
X
3
X
X
4
X
RET
X
X
5
X
6
X
RET
OUT
7
8
RET
INPUT
9
REFERENCE
10
RESISTOR
RET
X
x
11
x
X
x
12
X
x
X
x
RET
x
X
x
13
X
x
X
x
14
x
X
RET
OUT
15
16
+
–
SHLD
SERVICE
PORT
X X
X X
X X
F19, 3A, 250V
SLOW BLOW
F14
2 A
X
X
X
X
X
X
X
X
IN
X
x
x
X
x
X
x
X
x
x
X
x
X
x
X
x
x
X
IN
INFINET
LCD VIEW ANGLE
USE COPPER
CONDUCTORS ONLY
AC INPUT VOLTAGE SELECTION
24V
From
E1
E2 E5 E2 E2 E7
TP10
X
X
115V
To
To
From
E1
E3 E4
E7
TP10
E6 E6 E4
+
3.6 V
-
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
RESET
F1
1/8 A
X
X
X
X
From
TP10
Snap Latch
X
EPROM
230V
To
----
X
x
x
x
x
x
x
x
x
ADJ
X
ADJ
X
ADJ
ADJ
ADJ
ADJ
ADJ
ADJ
X
X
EXPANSION
PORT
- On
x
Off
Auto
x
+On
- On
+On
-On
+On
- On
+On
-O n
+On
- On
+On
-On
+On
+On
1
x
Form C
x
x
x
x
x
x
x
Tristate
2
x
3
x
x
4
5
x
x
6
x
7
Form C
Tristate
x
8
Off
x
Off
Auto
Off
x
Off
Auto
Off
x
Off
Auto
Off
x
Off
Auto
Off
x
Off
Auto
Off
x
Off
Auto
Off
x
Auto
Off
STATUS
x
CPU
x
TD
RD
x
x
OVERRIDE
x
+ 24 V
EXTERNAL
xx
1
2
3
1/8 A
4
5
1/8 A
6
7
1/8 A
8
X
Snap
NC
C
NO
I
V
GND
GND
I
V
NC
C
NO
NC
C
NO
I
V
GND
GND
I
V
NC
C
NO
NC
C
NO
I
V
GND
GND
I
V
NC
C
NO
NC
C
NO
I
V
GND
I
V
NC
C
NO
Latch
Snap
Latch
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
SCX 920 Installation Guide 15
Connecting the Battery
When you have the controller mounted, find the AA battery. Remove
the plastic tab below the clip on the battery to activate the battery.
The battery is an 850 mA-hr 3.6 V primary lithium battery that runs the
real-time clock and mainta ins RA M when AC power goes out.
Connecting the AC Power
Warning
Be sure the AC power cable is not connected to an electrical power
source while you are wiring the controller, or you could receive an
electrical shock that is life-threatening.
Hardware Instal lation
1
-- 2
The AC power connection is in the upper left corner of the controller.
You must wire the AC cable to the three scre ws on the far le ft .
Caution
Be sure to connect all three wires, HOT, NEUTRAL, and GROUND.
Otherwise, the controller could malfunction.
The three screws are labeled HOT NEU GND. The three wires at the
end of your AC cord are black, white, and green.
1. Place the green wire under the metal plate behind the top screw,
labeled GND.
2. Tighten the screw with a flathead screw driver.
Figure 4 shows the position of the plate, where to place the wire, and
how the screw fits on the plate. You can see how the screw holds
the plate in place once you tighten it.
16 SCX 920 Installation Guide
Hardware Installation
Figure 4. Metal Plate and Screw for Power Supply Wire
3. Place the white wire under the metal plate behind the middle screw,
labeled NEU.
4. Tighten the screw with a flathead screw driver.
5. Place the black wire under the metal plate behind the bottom screw,
labeled HOT.
Metal Plate
Insert Wire Here
6. Tighten the screw with a flathead screw driver.
Selecting the AC Input Voltage
The voltage is set to 115 V when shipped. To change the voltage, you
must reset the jumpers to the right of the AC power cord c onnec tion.
Table 4 shows jumper settings for the three voltages.
Table 4. Connecting Jumpers for AC Input Voltages
24V Jumpers 115V Jumpers 230V Jumpers
From To From To From To
E1 E3 E1 E4 — —
E2 E5 E2 E7 E2 E7
TP 10 E6 TP 10 E6 TP 10 E4
To change the voltage from 115 V to 24 V, proceed as follows:
1. Disconnect the jumper end from E4 and move it to E3 so it jumpers
E1 to E3 .
SCX 920 Installation Guide 17
2. Disconnect the jumper end from E7 and move it to E5 so it jumpers
E2 to E5 .
3. Leave the other jumper as it is.
To change the voltage from 115 V to 230 V, proceed as follows:
1. Disconnect the jumper from E1 to E4 and remove it.
2. Disconnect the jumper from E6 and connect it to E4, so it jumpers
TP10 to E4 .
3. Leave the other jumper as it is.
Wiring the Infinet to the SCX 920
Hardware Instal lation
Note
You mu s t use s hie ld ed ca bl es f o r Infinet to ensure compliance with the
Class A FCC limits and to ensure reliable communications.
Figure 5 illustrates how to wire the Infinet cable to the removable block
terminal connector in the lower left corne r of the SCX 920.
Figure 5. Infinet Cable Wiring
Infinet Connection
WHITE
BLACK
1. Trim back the shield over the wires.
+
WHITE
–
SHLD
BLACK
2. Take the first wire for the incoming Infinet and the first wire for the
outgoing Infinet and slip both in the hole beneath the screw labeled
with a plus sign (top).
18 SCX 920 Installation Guide
Hardware Installation
3. Tighten the screw down on them until the scr ew holds the wir es in
place.
4. Slip the second (usually black) wire from each Infinet cable under
the screw labeled with a minus sign (middle) and tighten the screw
down on them.
5. Slip the shields from the incoming and outgoing Infinet cables under
the screw labeled SHLD (bottom) and tighten the screw down on
them.
Wiring the Infinet to the Infinity CX 9000
You connect the last piece of Infinet cabl ing to the Infin ity CX 9000.
See the Infinity CX 9000 Hardware Installation Guide for instru ctions.
Setting the Input Reference Resistor Switches
The inputs are on the lower left side of the SCX 920. To the right of the
inputs are two DIP switches, with small switches for each input. Look
closely at the switch and notice that each small switch is numbered.
Each small switch corresponds to the input with the same number.
If an input is either a thermistor or a digital input, switch its input reference resistor switch to IN. If you require the input be high impedance
(10 MΩ), set its input reference resistor switch to OUT.
Wiring the Inputs
Caution
Do not remotely ground any part of the sensor wiring. Remote grounds
connected to the SCX 920 return terminal could make the controller
operate incorrectly or damage the equipment. The signal return is not
true earth ground. It is an electronic reference point necessary to
interpret the sensor properly. Do not externally ground sensor or switch
terminals that return to the SCX 920.
SCX 920 Installation Guide 19
Hardware Instal lation
Caution
Although inputs usually function properly with unshielded sensor wire,
you may need shielded wire if you run the wire as follows:
• In the same conduit with other noise-generating conductors such as
60 Hz AC power.
• In long runs close to large power-consuming or power-generating
equipment that can produce 60 Hz noise.
We recommend you run input wiring in a conduit separate from AC
power or output wiring and avoid long wiring runs.
Caution
Follow the rules below when wiring inputs and outputs:
• Never lay wires across the surface of t he printed circuit board. You
should bring input wires in from the left and output wires in from the
right.
• Bundle excess wires toward the back of the cabinet to avoid any
contact with circuit boards.
• Wires should never be within 1 in. of any component on the printed
circuit board.
• Keep cabinet free of foreign materials (extra power supplies, relays,
and so on).
• Be careful when stripping wire not to drop small pieces of wire
inside the cabinet.
If you violate any of these rules, the controller could malfunction.
Caution
Never apply a voltage to a thermistor. Doing so alters the thermistor’s
accuracy and reliability. You should replace a thermistor that has had
voltage applied to it. Never bring a soldering iron to within 3 inches of
the thermistor’s sensing tip.
20 SCX 920 Installation Guide
Hardware Installation
The inputs are on the lower left side of the SCX 920. Input wires should
enter from that side. Notice that the inputs are labeled RET, 1, 2, RET,
3, 4, and so on. The first return terminal goes to the first two inputs, the
second to the next two inputs, and so on.
Figure 6 shows a thermistor attached to an input point. One lead
connects to the numbered input terminal, the other to a return terminal.
Figure 6. Wiring Diagram for Thermistor Input
1 (input point 1)
RET (return)
Follow these steps:
1. Slip the first wire for the first sensor under the input point screw for
input 1 and tighten the screw down on it.
2. Slip the first wire for the second sensor under the input point screw
for input 2 and tighten the screw down on it.
3. Slip the ground wires from both the first and second sensors under
the RETURN screw above input point 1 and tighten the screw down
on them.
4. Repeat the steps 1 through 3 for each pair of inputs.
Figure 7 shows a counter wired to an input point.
Figure 7. Wiring Diagram for Counter or Digital Input
1 (input point 1)
RET (return)
SCX 920 Installation Guide 21
Hardware Instal lation
Figure 8 shows a voltage sensor wired to an input point.
Figure 8. Wiring Diagram for Voltage Input
1 (input point 1)
+
V
–
RET (return)
Figure 9 shows a current sensor wired to an input point. You must set
the reference res is tor switch to OUT for a current inp ut. T he n wire a
resistor across the input.
Figure 9. Wiring Diagram for Current Input
1 (input point 1)
RL= 475Ω with wattage
1
-- -
RET (return)
rating
≥
4
Watt
The exact number of Ohms resistance required varies based on the range
of current—while we recommend 475Ω for a 0 to 20 mA input, yo u can
also calc u late the approp riate resistan ce w ith the follow ing formula:
VINV
max
R
-----------------------
max
I
mA
1000×=
To account for the input current rising slightly above the maximum
(such as slightly over 20 mA), you should choose a value slightly below
the maximum resistance you calculate. For example, you calculate the
resistance for 0 to 20 mA:
10
max
R
22 SCX 920 Installation Guide
----- -
1000× 500Ω==
20
Hardware Installation
You then select the next standard resistor, 475Ω, with a 0.1% or 1% tolerance. (The accuracy of the input is directly proportional to the
tolerance of the resistor . So the lower the tolerance, the greater the ac-
curacy.) The wattage rating should be greater than or equal to watt.
Be sure you check the Infinity CX Controller Programmer’s Guide for
details on how to convert the voltage from a current input to other units.
Wiring the Outputs
Wiring Tristate Outputs
The outputs are down the entire right side of the SCX 920. All output
wires should enter from the right. Notice that the first output is labeled
from top to bottom NC, C, NO, I, V, GND. The next GND starts the
second output, labeled GND, I, V, NC, C, NO.
1
-- 4
You can wire a pair of output relays, one odd numbered output and the
subsequent even numbered output, to control one tristate output. When
you do, the odd numbered override switch controls the tristate output.
You can then use the even numbered switch to control an analog (current or voltage) output, but no t a Form C output.
(Because of this option, you can have up to four tristate and four analog
outputs on the same board.)
To set any of the four pairs of outputs to a tristate output, proceed as
follows:
1. Find the slide switch to the right of the pair of override rotary
switches. Set the switch to the down position (marked TRISTATE
on the top and bottom switches only, but applic ab le to al l of them) .
The tristate output connects to four terminations only—Common,
+ON, Normally Closed (NC, equivalent to OFF), and –ON.
2. Wire the tristate output as shown in the diagram ins ide the front
cover of the controller.
Figure 10 shows the diagram also.
SCX 920 Installation Guide 23
Hardware Instal lation
3. Slip appropriate wire under each screw and tighten the screw down
on it.
4. When switching inductive loads (relays, contactors, motors, or
valves), be sure to install metal oxide varistors across the coil of the
device being switched.
Figure 10. Wiring Diagram for Tristate Outputs
NC
ODD
OUTPUT
EVEN
OUTPUT
C
NO
NC
C
NO
Wiring Analog Outputs—Voltage
The outputs are on the upper right side of the SCX 920. All output wires
should enter from the right.
You wire the outputs for voltage as follows:
1. Slip the appropriate wire under the V screw and tighten the screw
down on it.
C
+ON
OFF
–ON
Figure 11 illustrates the wirin g for voltage outputs.
2. Slip the ground wire under the GND screw and tighten the screw
down on it.
24 SCX 920 Installation Guide
Hardware Installation
Figure 11. Wiring Diagram for Voltage Outputs
+
–
GND
GNDGND
V
Wiring Analog Outputs—Current
The outputs are on the upper right side of the SCX 920. All output wires
should enter from the right.
You wire the outputs for current as follows:
Caution
Remember that the current sources to ground.
1. Slip the appropriate wire under the I screw and tighten the screw
R
> or = 4K
L
Ω
down on it.
Figure 12 illustrates the wirin g for curr ent outputs.
2. Slip the ground wire under the GND screw and tighten the screw
down on it.
Figure 12. Wiring Diagram for Current Outputs
I
GNDGNDGND
Wiring Form C Outputs
The outputs are on the upper right side of the SCX 920. All output wires
should enter from the right.
RL < or = 750
Ω
SCX 920 Installation Guide 25
Hardware Instal lation
You wire the outputs for Form C as follows:
1. Slip the appropriate wire under the NC screw and tighten the screw
down on it.
2. Slip the appropriate wire under the C screw and tighten the screw
down on it.
3. Slip the appropriate wire under the NO screw and tighten the screw
down on it.
4. When switching inductive loads (relays, contactors, motors, or
valves), be sure to install metal oxide varistors across the coil of the
device being switched.
Figure 13 shows the schematic for wiring a Form C output.
Figure 13. Wiring Diagram for Form C Outputs
Setting the Override Switches
The eight five-position override rotary switches let you either manually
control each output or set it to AUTO so the controller can control it.
Figure 14 shows a close-up of a single override rotary switch and how
the settings change for voltage, current, or Form C.
NC
C
NO
26 SCX 920 Installation Guide
Hardware Installation
Figure 14. Five Positions on Odd Numbered Override
Switch
- On
Off
Auto
Off
x
+On
Already Marked for Tristate Outputs
The five positions on any odd numbered switch set the output as marked
if it is tristate. If you use the odd numbered output as a voltage or current output, both ON and –ON set the output to ON. If you use the odd
numbered output as a Form C output, –ON does not set the output to
ON, but all other switches set the output as marked.
Table 5 shows how switch settings change for the different outputs .
Table 5. Corresponding Override Switch Settings
for Different Outputs Types
Tristate Form C Voltage Current
–ON Not Applicable ON ON
OFF OFF OFF OFF
AUTO AUTO AUTO AUTO
OFF OFF OFF OFF
+ON ON ON ON
Connecting Modules to the Expansion Port
The expansion port at the bottom center of the controller board allows
you to connect modules to expand the capabilities of the controller.
Contact your Andover Controls representative for more information on
expansion modules.
SCX 920 Installation Guide 27
Powering Up the SCX 920
Warning
Before powering up the controller, be sure the board is jumpered for the
correct input voltage.
Before you proceed, be sure the following are correct:
1. Be sure you have jumpered the proper input voltage.
2. Be sure the battery is conne cte d.
3. Be sure the AC power is wired properly. Check to be sure all three
wires have been connected.
Hardware Instal lation
4. Be sure the controller has a true earth ground.
5. Be sure you have used the proper cables and wires and correct
lengths.
6. Be sure you have properly labeled the tag with the name of the
controller before removing it.
7. Be sure the Infinet cable has been properly wired.
8. Be sure the Infinet cable shields are properly connected.
If you have completed all previous sections in this manual, you are now
ready to power up the controller.
Turn on the AC power source (or close the power connection) and the
controller starts automatically. The following occurs (also occurs when
you press RESET):
1. If the controller has been off, relays remain off. If you have pressed
RESET, relays de-e nergize.
2. If the controller has been off, analog outputs remain off. If you have
pressed RESET, analog outputs are set to 0 V.
28 SCX 920 Installation Guide
Hardware Installation
3. If you are pressing RESET, the OVERRIDE light turns on while you
are pressing the button.
4. The CPU light begins flashing and flashes every .2 sec.
5. The TD light immediately starts flashing after you let go of the
button to show data is being transmitted.
6. The RD light begins flashing only if data is being received from
other controllers on the network. This may not happen immediately.
7. If any of the eight outputs is not set to AUTO, the overrides are
enabled and the OVERRIDE light remains steadily on.
8. If the CPU light flashes every .1 sec, it means the CPU has failed a
RAM or ROM test. See the Andover Controls Inf inet Co ntr oller
Troubleshooting Guide.
9. The EXTERNAL +24V light turns on and remains steadily on.
When the EXTERNAL +24V light goes out, it means no power is
being supplied to the expansion port. You may have to replace the
fuse. See the Andover Controls Infinet Controller Troubleshooting
Guide.
10. The eight status lights on the front of the controller each correspond
to the output with the same number. They remain off until their
corresponding outputs are turned ON by the controller programs. If
no programs are running, the lights remain off. Pulsed outputs flash
on for the duration of the pulse and then go off.
Reset Button
The RESET button is the red square button just left of the vertical center
of the board near the bottom. You press it to initiate a warm start. The
same events occur for a warm start as for a cold start.
Adjusting the LCD View Angle
The LCD VIEW ANGLE adjustment screw is at the top in the center of
the board (see Figure 3). You turn the screw to adjust the angle of the
LCD on the front cabinet.
SCX 920 Installation Guide 29
Hardware Instal lation
The contrast changes at different viewing angles. Adjust it to your
needs.
Completing the Installation
To complete the installation of your SCX 920 replace the cabinet cover,
using the two Phillips head quarter turn fasteners.
Connecting the Andover Controls Service Tool
The SERVICE PORT on the far left side of the bottom of the controller
is to connect the Andover Controls Service Tool to a SCX 920. The service tool will access all SCX 920s an d other Infinet controllers on the
same network. For information on availability of the Andover Controls
Service Tool, contact your Andover Controls representative.
Adjusting Analog Override Values
Refer to Figure 3 for the location of part on the board.
To manually set an output’s current or voltage:
1. Turn the override switch for the output to ON.
2. If you do not have an LCD screen, connect a Volt-Ohm Meter
(VOM) to the V or I terminal of the output.
3. Use a small screwdriver in the ADJ screw to the left of the override
switch to adjust the screw until the correct value of the output is
displayed on the LCD screen or meter.
A correct value would be between 0 and 20 mA or 0 and 20 V.
30 SCX 920 Installation Guide
Index
A
AC power
connecting 16
AC voltage
setting 17
accuracy
wire gauge factors 7
adjustment
LCD view angle 29
Andover Controls Service Tool
using 30
B
backup power
connecting 16
battery
connecting 16
C
cabinet
dimensions 3
weight 3
cable
for Infinet 4
length 3
circuit requirements for power 3
configuration
planning 9
counter inputs
wiring 21
cover
removing front 10
replacing 30
current outputs
wiring 25
current sensors
resistor required 22
wiring 22
D
dimensions
cabinet 3
dimensions to knockouts 12
E
enclosure
Underwriter Laboratories
requirements 5, 10
environments
for operating 5
expansion modules
connecting 27
expansion port
purpose 27
F
Form C outputs
wiring 25
front cover
removing 10
replacing 30
G
ground
correcting 5
inspecting 5
requirements 4
I
Infinet
lightning arrester for 4
Infinet cable
connecting 18
Infinet cable numbers 4
input reference resistor switch
setting 19
inputs
circuit specifications 7
current
resistor tolerance 23
SCX 920 Installation Guide Index-1
wiring rules 20
R
J
jumpers
setting for AC voltage 17
K
knockouts
dimensions 12
L
LCD view angle
adjusting 29
lightning arrester
for Infinet 4
M
manual overrides
disabling 10, 12
mounting 10
O
outputs
equipment requirements 6
wiring 23
wiring rules 20
override rotary switches
setting 26
RESET button 29
resistors
to wire across current inputs 22
tolerance required 23
S
screw holes
locations for mounting 12
sensors (see wiring)
service port
purpose of 30
shields
for Infinet cable
connecting 19
required for sensor wire 20
slide switches
purpose 14
T
temperatures
for operating 5
thermistors
reducing errors 7
wiring 21
tristate outputs
wiring 23
U
P
parts
inside the controller 14
points (see wiring)
power
battery backup 16
power requirements
circuit 3
power surges
preventing 4
powering up
preparations for 28
Index-2 SCX 920 Installation Guide
Underwriter Laboratories
enclosure requirements 5, 10
V
varistors
when to use 24
voltage
selecting for AC power 17
voltage outputs
wiring 24
voltage sensors
wiring 22
W
weight
cabinet 3
wires
gauge for thermistors 7
wiring
AC power connection 16
connecting Infinet cable 18
correct wire gauge for ground 5
counter inputs 21
current outputs 25
current sensors 22
Form C outputs 25
inputs 19
outputs 23
rules for inputs and outputs 20
thermistors 21
tristate outputs 23
voltage outputs 24
voltage sensors 22
SCX 920 Installation Guide Index-3
Index-4 SCX 920 Installation Guide
30-3001-170 SCX 920 Installation Guide Rev D
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