Lake Shore Model 218 Temperature Monitor User’s Manual
Installation
3-3
3.3.1.1 Line
Voltage
The Model 218 has four different AC line voltages configurations so that it can be operated from
line power anywhere in the world. The nominal voltage and voltage range of each configuration is
shown in Table 3-1. (The recommended setting for 230 V operation is 240 V.)
Table 3-1. AC Line Input Definitions
Nominal Minimum Maximum
100 V
90 V
106 V
120 V
108 V
127 V
220 V
198 V
233 V
240 V
216 V
254 V
Verify that the AC line voltage indicator in the fuse drawer window shows the appropriate AC line
voltage before turning the instrument on. The instrument may be damaged if turned on with the
wrong voltage selected. Instructions for changing the line voltage configuration are given in
Paragraph 7.4.
3.3.1.2
Line Fuse and Fuse Holder
The line fuse is an important safety feature of the Model 218. If a fuse ever fails, it is important to
replace it with the value and type indicated on the rear panel for the line voltage setting. The letter
"T" on the fuse rating indicates that the instrument requires a time-delay or slow-blow fuse. Fuse
values should be verified any time line voltage configuration is changed. Instructions for changing
and verifying a line fuse are given in Paragraph 7.5.
3.3.1.3 Power
Cord
The Model 218 includes a 3-conductor power cord that mates with the IEC 320-C14 line cord
receptacle. Line voltage is present on the two outside conductors and the center conductor is a
safety ground. The safety ground attaches to the instrument chassis and protects the user in case
of a component failure. A CE approved power cord is included with instruments shipped to Europe;
a domestic power cord is included with all other instruments (unless otherwise specified when
ordered). Always plug the power cord into a properly grounded receptacle to ensure safe
instrument operation.
The delicate nature of measurement being taken with this instrument may necessitate additional
grounding including ground strapping of the instrument chassis. In these cases the operators safety
should remain the highest priority and low impedance from the instrument chassis to safety ground
should always be maintained.
3.3.1.4 Power
Switch
The power switch is part of the line input assembly on the rear panel of the Model 218 and turns
line power to the instrument On and Off. When the circle is depressed, power is Off. When the line
is depressed, power is On.
