Chromalox 3901 User Manual
Chromalox
3901
Chromalox
®
Overtemperature Controller
Issue Date
Dec 1993
User’s Manual
0037-75121
U
L
®
FM
APPROVED
i Chromalox 3901 User’s Manual
Table of Contents
Sections
Section Topic Page
1 Introduction to the 3901 Controller 1
2 Installation 3
3 Operation 9
4 Calibration 13
5 Specifications 15
6 Warranty and Return Information 17
Illustrations
Figure Topic Page
1.1 Overtemperature Control Application 1
1.2 Model Identification Table 2
2.1 Removing the Back Cover 4
2.2 Mounting Dimensions 4
2.3 Mounting Diagram 5
2.4 Wiring Connections 7
3.1 Front Panel Identification 10
3.2 Set Point Limit Potentiometer 12
4.1 Zero and Span Calibration Potentiometer 13
Chromalox 3901 User’s Manual 1
The Chromalox 3901 Overtemperature Controller
gives you reliable and economical digital indicating,
overtemperature control in a compact 1/4 DIN
package. Figure 1.1 illustrates a typical overtemperature application.
Figure1.1
Overtemperature Control Application
Chromalox
READ
TEMP
ALARM
HEAT
SOURCE
SHUTDOWN
CONTACTOR
3901
°
F
OVERTEMP FOR PROCESSOR HEATER SHEATH PROTECTOR
Chromalox
READ
TEMP
ALARM
3901
°F
FLOW
SWITCH
LEVEL
CONTROL
SHUTDOWN
CONTACTOR
AIR
FLOW
LEVEL
SENSOR
HEAT
SOURCE
OVERTEMP APPLIED WITH OTHER CUTOUT DEVICES
Section 1
Introduction to the
3901 Controller
2 Chromalox 3901 User’s Manual
Before You
Install
Before proceeding with installation and operation of
your controller, it is important that you identify the
model you have purchased. This will determine how
you install and wire the controller, and how you may
apply it. Check the serial number tag on the inside
front door flap of the controller to confirm your
model number.
Figure 1.1
Model Identification Table
Model Overtemperature Controller
3901 Digital Indicating, UL Listed, FM Approved, Terminals for Remote Reset;
1/4 DIN Panel Cutout, 2.4 Inch Depth Behind Panel
Code Control Output
1 Relay, up to 230 Vac, 20 amp resistive load, SPST Latching,
Normally-Energized, Normally-Open Contact
Code Terminations
1 Barrier Strip with Screw Terminals
Code Instrument Power
1 120 Vac, +10%, -15%, 50/60 Hz
2 230 Vac, +10%, -15%, 50/60 Hz
Code Input Type/Indication Range
04 Type J Thermocouple, 0-999°F
08 Type J Thermocouple, 0-500°C
12 Type K Thermocouple, 0-1999°F
18 Type K Thermocouple, 0-1100°C
3901- 1 1 1 04 Typical Model Number
Chromalox 3901 User’s Manual 3
Section 2
Installation
Inspection &
Unpacking
On receipt of your 3901 controller, immediately make
note of any visible damage to the shipment packaging
and record this damage on the shipping documents.
Unpack the controller and carefully inspect it for
obvious damage due to shipment. If any damage has
occurred, YOU must file a claim with the transporter,
as they will not accept a claim from the shipper.
Storage If the controller will not be immediately installed and
placed into operation, it should be stored in a cool, dry
environment in its original protective packaging until
time for installation and operation. Temperature
extremes and excessive moisture can damage the
instrument.
Installation
Steps
Installation of the 3901 controller requires 3 steps:
Step 1 - Accessing Internal Adjustments
Step 2 - Mounting
Step 3 - Wiring
Step 1
Accessing
Internal
Adjustments
The back cover of the 3901 can be easily removed to
access the following internal adjustment:
• Set Point Limit Potentiometer (page 11)
The page number referenced above describes this
internal adjustment. Although it is not necessary, it is
easier to make this adjustment prior to mounting
and wiring the controller. If you want to establish a
Set Point Limit for your controller, read the page
referenced above before mounting and wiring the
3901.
4 Chromalox 3901 User’s Manual
To remove the back cover, loosen the two back cover
screws shown in Figure 2.1 and lift the cover off of
the controller chassis.
Loosen screw
Loosen screw
After completing the internal adjustment(s), replace
the cover and re-secure the two screws.
Step 2
Mounting
The controller should be mounted in a location free
from excessive dust, oil accumulations and moisture.
It may be mounted in any position at ambient
temperatures of 30°F to 130°F (0°C to 55°C).
Figure 2.2 gives the mounting dimensions for the
controller.
Chromalox
READ
TEMP
ALARM
3.8
(96)
3.8
(96)
2.4
(61)
.8
(19)
3.6
(92)
3.5
(89)
PANEL CUTOUT
Measurements are shown in inches.
Millimeters are shown in parenthesis.
Figure 2.2
Mounting
Dimensions
Figure 2.1
Removing the
Back Cover
WARNING
TO REDUCE THE RISK OF FIRE OR ELECTRIC
SHOCK, PANEL MOUNT IN A CONTROLLED
ENVIRONMENT ENCLOSURE RELATIVELY FREE
OF CONTAMINANTS.
HAC
LAC/N
120 V AC
230 VAC
5 VA
1
2
3
4
5
6
CASE GND
7
8
+
REMOTE
RESET
INTERNAL
ALARM
RELAY
U
L
®
LISTED
35MO
20A RES 55 C 120/230 VAC
RELAY RATING
FM
APPROVED
TC INPUT
NOTE: USE COPPER CONDUCTORS ONLY
Loading...