
Lake Shore Model 340 Temperature Controller User’s Manual
3-6
Installation
3.3.3 Fuse
Replacement
Below is the procedure to remove and replace a line fuse. Use slow blow fuses with the value shown in
Table 3-1. To change line input from the factory setting, use the appropriate fuse in the connector kit shipped
with the instrument.
1. Locate the line input assembly on the instrument rear panel.
2. Turn the power switch OFF (
O
).
3. Remove the instrument power cord.
4. With a small screwdriver, release the drawer holding the line
voltage selector and fuse.
5. Remove fuse and replace it with the appropriate slow blow fuse.
6. Re-assemble the line input assembly in reverse order.
7. Verify voltage indicator in the line input assembly window.
8. Connect the instrument power cord.
9. Turn the power switch ON (
l
).
3.3.4 Power
Cord
The Model 340 includes a three-conductor power cord. Line voltage travels across the outer two conductors.
The center conductor is a safety ground and connects to the instrument metal chassis when the power cord
attaches to the power connector. For safety, plug the cord into an appropriate
grounded
receptacle.
3.3.5 Power
Switch
The power switch turns the instrument ON and OFF and is located in the line input assembly on the
instrument rear. When
l
is raised on the switch, the instrument is ON; when
O
is raised, the instrument is
OFF. Do not remove instrument covers without first disconnecting the power cord, even if the instrument
power switch is off.
3.4 STANDARD
SENSOR
INPUTS
This paragraph details how to connect sensors to the standard Model 340 inputs. These inputs operate with
most resistive and diode sensors. Refer to Paragraph 5.1 to configure inputs for a sensor type with software.
Some sensor types require an optional input which is discussed in Chapter 10.
This section covers sensor input connector and pinout in Paragraph 3.4.1, sensor lead cable in Paragraph
3.4.2, grounding and shielding sensor leads in Paragraph 3.4.3, sensor polarity in Paragraph 3.4.4, four-lead
sensor measurement in Paragraph 3.4.5, two-lead sensor measurement in Paragraph 3.4.6, and lowering
measurement noise in Paragraph 3.4.7.
3.4.1 Sensor Input Connector and Pinout
The input connectors are 6-pin DIN 45322 sockets. The sensor output pins are defined in Table 3-3. Two
mating connectors (6-pin DIN plugs) are included in the connector kit shipped with the instrument. These are
common connectors, so additional mating connectors can be purchased from local electronics suppliers.
They can also be ordered from Lake Shore (P/N 106-233).
Table 3-3. Sensor INPUT A and B Connector Definition
l+
V+
l -
V-
INPUT A
INPUT B
l+
V+
l -
V-
Power On/Off
Switch
Fuse
Drawer
Screwdriver
Slot
Figure 3-3. Power Fuse Access
Pin Symbol
Description
1 I– Minus
Current
Terminal
2
V–
Minus Voltage Terminal
3
Shield
Driven Shield or Guard
4 V+ Plus
Voltage
Terminal
5
I+
Plus Current Terminal
6
No
Connection