1. Safety Instructions

1.1. Introduction

Read this chapter carefully before you install and use the instrument.

This instrument has been designed and tested for Measurement Category I, Pollution Degree 2, in accordance with EN/IEC 61010-1:2001 and CAN/CSA-C22.2 No. 61010-1-04 (includ-ing approval). It has been supplied in a safe condition. The user of this instrument must have sufficient knowledge of it. This knowl-edge can be gained by thoroughly studying this manual, especially the sections on Safety Pre-cautions and Installation in this chapter.

This instrument is designed to be used by trained personnel only. Removal of the cover forrepairorrack-mountingofthe instrument must be done by qualified personnel who are aware of the hazards involved. There are no user-serviceable parts inside the instrument.

1.2. Safety Precautions

All equipment that can be connected to line power is a potential danger to life. Handling re-strictions imposed on such equipment should be observed.

To ensure the correct and safe operation of this instrument, it is essential that you follow gener-ally accepted safety procedures in addition to the safety precautions specified in this manual.

The warranty commitments are rendered void if unauthorized access to the interior of the instrument has taken place during the given warranty period.

1.2.1. Caution and Warning Statements

CAUTION: Shows where incorrect procedures can cause damage to, or destruction of equipment or other property.

WARNING: Shows a potential danger that requires correct procedures or practices to prevent personal injury.

1.2.2. Symbols

Shows where the protective ground terminal is connected inside the instrument. Never remove or loosen this screw

This symbol is used for identifying the functional ground of an I/O signal. It is always connected to the instrument chassis.

Indicates that the operator should consult the manual.

1.2.3. If in Doubt about Safety

Whenever you suspect that it is unsafe to use the instrument, you must make it inoperative by doing as follows:

  • Disconnect the line cord.
  • Clearly mark the instrument to prevent its further operation.
  • Inform your local Pendulum Service Center.

For example, the instrument is likely to be un-safe if it is visibly damaged.

2. Unpacking

2.1. Unpacking Instructions

Check that the shipment is complete and that no damage has occurred during transportation. If the contents are incomplete or damaged, file a claim with the carrier immediately. Also notify your local Pendulum sales or service office in case repair or replacement may be required.

2.1.1. Check List

The shipment should contain the following:

  • The frequency standard.
  • A line cord.
  • A CD with PDF manuals for Pendulum products, e.g. this manual.
  • If you ordered one or two of the output options (70B, 71B, 72B, 73B, 74B), or the disciplining option (79/01), or one of the DC supply options (77, 78, 78/HS), they should already be installed. See “Identifi-cation” below.

The warranty commitments are rendered void if unauthorized access to the interior of the instrument has taken place during the given warranty period.

  • If you ordered one of the DC supply op-tions (77, 78/HS), a three-pole power D- sub socket connector is included that mates with the corresponding rear panel pin connector. It is intended for making a wire harness suitable for linking the instru-ment to an external DC power source.
  • Other options you ordered, e.g. antenna (option 01), antenna cable (option 02), rack mount kit (option 22) or carrying case (option 27/27H) are shipped in sepa-rate boxes.
  • Certificate of Calibration.

2.1.2. Identification

Options installed inside the cover are identified on the rear panel according to the list below. Up to two output boards in any combination can be fitted at the same time. The combined I/O board

Option 79/01 is an exception. Only one such board can be fitted. However, it can be com-bined with any other output board.

Option 70B: 4 BNC-connectors mounted in the area designated.

Option 71B: 4 BNC-connectors mounted in the area designated.

Option 72B: 4 BNC-connectors mounted in the area designated.

Option 73B: 4 BNC-connectors mounted in the area designated.

Option 74B: 4 BNC-connectors mounted in the area designated.

Option 77: -48 VDC power supply & rear panel power D-sub connector.

Option 78: Internal 16 VDC rechargeable bat-tery for GPS-12(R)

Option 78/HS: Internal 16 VDC rechargeable battery & rear panel power D-sub connector for ext. 12 VDC source. Intended for GPS-12R/HS and GPS-12RG.

Option 79/01: 4 BNC-connectors mounted in the area designated.

3. Installation

3.1. Supply Voltage

3.1.1. Setting

The GPS-12X frequency standard can be con-nected to any AC supply with a voltage rating of 90 to 265 Vrms, 45 to 440 Hz. The frequency standard automatically adjusts itself to the in-put line voltage.

Depending on option chosen, the unit can also be supplied by external DC sources, -48 V or+12 V.

3.1.2. Fuse

The secondary supply voltages are electroni-cally protected against overload or short cir-cuit. The primary line voltage side is protected by a fuse located on the power supply unit. The fuse rating covers the full voltage range. Con-sequently there is no need for the user to re-place the fuse under any operating conditions, nor is it accessible from the outside.

CAUTION: If this fuse is blown, it is likely that the power supply is badly damaged. do not replace the fuse. Send the frequency standard to the local Pendulum Service Cen-ter.

3.1.3. Grounding

Grounding faults in the line voltage supply will make any instrument con-nected to it dangerous. Before con-necting any unit to the power line, you must make sure that the protective ground functions correctly. Only then can a unit be connected to the power line and only by using a three-wire line cord. No other method of grounding is per-mitted. Extension cords must always have a protective ground conductor.

WARNING: If a unit is moved from a cold to a warm environment, con-densation may cause a shock hazard. Ensure, therefore, that the grounding requirements are strictly met.

WARNING: Never interrupt the grounding cord. Any interruption of the protective ground connec-tion inside or outside the instrument or disconnection of the protective ground terminal is likely to make the instrument dangerous.

3.2. Power Switch

This instrument is equipped with a secondary power switch. It disconnects the main power-consuming circuits on the secondary side of the power supply but leaves the rubid-ium oscillator active in order to retain its long-term characteristics. Line voltage is al-ways present on the primary side.

WARNING: Always consider the instrument active as soon as it is connected to the primary AC power source with a power cord.

3.3. Orientation and Cooling

The frequency standard can be operated in any position desired. Make sure the air flow through the ventilation slots are not obstructed. Leave 50 mm (2 in) of space around the instrument.

CAUTION: Never cover the ventilation slots at the right or left side. If the slots are covered, the fre-quency standard will overheat.

3.3.1. Fan Control

The speed-controlled fan is used for adjusting the temperature inside the frequency standard to compensate for variations in ambient tem-perature.

Fig 2-1. Air flow through the GPS-12X.

3.4. Fold-down Support

For bench-top use, a fold-down support is available for use underneath the frequency standard. This support can also be used as a handle to carry the instrument.

Fig. 2-2. Fold-down support for comfort-able bench-top use.

3.5. Rackmount Adapter

Fig. 2-3. Dimensions for rackmounting hardware.

If you have ordered a 19 inch rack mount kit for your instrument, it has to be assembled after de-livery of the instrument. The rack mount kit consists of the following:

2 brackets, (short, left; long, right)
4screws, M5x8
4screws, M6x8

WARNING: When you remove the cover you will expose live parts and accessible terminals which can cause death.

WARNING: Capacitors inside the instrument can hold their charge even if the instrument has been separated from all voltage sources.

Fig. 2-6. Fitting the rackmount brackets on the counter.

3.5.1. Assembling the Rackmount Kit

  • Make sure the power cord is disconnected from the instrument.
  • Turn the instrument upside down.
  • See Figure 2-4.
  • Undo the two screws (A) and remove them from the cover.
  • Remove the rear feet by undoing the two screws (B).
  • Remove the four decorative plugs (C) that cover the screw holes on the right and left side of the front panel.
  • Grip the front panel and gently push at the rear.
  • Pull the instrument out of the cover.