Omega Engineering CYD201 and CYD208 manual Power and Ground Requirements

OMEGA Model CYD201/CYD208 User’s Manual

2.3POWER AND GROUND REQUIREMENTS

The Model CYD201/CYD208 requires a power source of 90 to 125 or 210 to 250 VAC, 50 or 60 Hz, single phase, 3 Watts. Three-prong detachable power cord for 120 VAC operation included. Connect to rear panel UL/IEC/ICEE standard plug. See Table 2-1 for fuse rating.

WARNING: To prevent electrical fire or shock hazards, do not expose this instrument to rain or excess moisture.

CAUTION: Verify proper fuse installation and AC Line Voltage Selection Wheel on the Model CYD201/CYD208 rear panel set to available AC line voltage before inserting power cord and turning on the instrument.

Refer to Chapter 5 to change voltage configuration.

NOTE: Do not attach the shield to earth ground at the sensor end. It may introduce noise at the measurement end.

Table 2-1. Line Voltage and Fuse Rating Selection

Select	Range	Fuse
115	90 – 125 VAC	0.2 A (Slow Blow)
230	210 – 250 VAC	0.1 A (Slow Blow)

To protect operating personnel, the National Electrical Manufacturer’s Association (NEMA) recommends, and some local codes require, grounded instrument panels and cabinets. The 3-conductor power cable, when plugged into an appropriate receptacle, grounds the instrument.

Grounding and shielding signal lines are major concerns when setting up any precision instrument or system. The CYD201/CYD208 includes ground isolation of sensor excitation to allow 4-wire measurement of diode voltage and resistance. Improperly grounding sensor leads and shields can defeat this feature.

Model CYD201/CYD208 digital logic ties directly to earth ground for interface communication. The low side of the heater output connects directly to earth ground. Shield sensor cables whenever possible. Attach the shields to the connector shield pin.

2.4SENSOR INSTALLATION RECOMMENDATIONS

See the OMEGA Product Catalog for sensor installation and specifications. Call OMEGA for copies of application notes or sensor installation questions. Below are general recommendations on sensor installation:

1.Do not ground the sensor.

2.Shield leads and connect shield wire to SHIELD on screw terminal connector only. Do not connect shield at other end of cable.

2-2 Installation