Keithley 2700, Service Manual

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Safety Precautions
The following safety precautions should be observed before using this product and any associated in-
strumentation. Although some instruments and accessories would normally be used with non-hazardous
voltages, there are situations where hazardous conditions may be present.
This product is intended for use by qualified personnel who recognize shock hazards and are familiar
with the safety precautions required to avoid possible injury. Read the operating information carefully
before using the product.
The types of product users are:
Responsible body is the individual or group responsible for the use and maintenance of equipment, for
ensuring that the equipment is operated within its specifications and operating limits, and for ensuring
that operators are adequately trained.
Operators use the product for its intended function. They must be trained in electrical safety procedures
and proper use of the instrument. They must be protected from electric shock and contact with hazardous
live circuits.
Maintenance personnel perform routine procedures on the product to keep it operating, for example,
setting the line voltage or replacing consumable materials. Maintenance procedures are described in the
manual. The procedures explicitly state if the operator may perform them. Otherwise, they should be
performed only by service personnel.
Service personnel are trained to work on live circuits, and perform safe installations and repairs of prod-
ucts. Only properly trained service personnel may perform installation and service procedures.
Exercise extreme caution when a shock hazard is present. Lethal voltage may be present on cable con-
nector jacks or test fixtures. The American National Standards Institute (ANSI) states that a shock haz-
ard exists when voltage levels greater than 30V RMS, 42.4V peak, or 60VDC are present.
A good safety
practice is to expect that hazardous voltage is present in any unknown circuit before measuring.
Users of this product must be protected from electric shock at all times. The responsible body must en-
sure that users are prevented access and/or insulated from every connection point. In some cases, con-
nections must be exposed to potential human contact. Product users in these circumstances must be
trained to protect themselves from the risk of electric shock. If the circuit is capable of operating at or
above 1000 volts,
no conductive part of the circuit may be exposed.
As described in the International Electrotechnical Commission (IEC) Standard IEC 664, digital multi-
meter measuring circuits (e.g., Keithley Models 175A, 199, 2000, 2001, 2002, and 2010) are Installation
Category II. All other instruments’ signal terminals are Installation Category I and must not be connect-
ed to mains.
Do not connect switching cards directly to unlimited power circuits. They are intended to be used with
impedance limited sources. NEVER connect switching cards directly to AC mains. When connecting
sources to switching cards, install protective devices to limit fault current and voltage to the card.
Before operating an instrument, make sure the line cord is connected to a properly grounded power re-
ceptacle. Inspect the connecting cables, test leads, and jumpers for possible wear, cracks, or breaks be-
fore each use.
For maximum safety, do not touch the product, test cables, or any other instruments while power is ap-
plied to the circuit under test. ALWAYS remove power from the entire test system and discharge any
capacitors before: connecting or disconnecting cables or jumpers, installing or removing switching
cards, or making internal changes, such as installing or removing jumpers.