Toshiba CTX28 manual AC Power and Third-wire Ground Test, Alternate or Additional Ground

Strata CTX100-S/CTX100 Installation

AC Power and Grounding Requirements

AC Power and Third-wire Ground Test

Test the “third-wire ground” for continuity by either measuring the resistance between the third prong terminal (earth ground) and a metal cold water pipe (maximum: 1 ohm), or by using a commercially available earth ground indicator. If neither procedure is possible, perform the following earth ground test procedure.

WARNING! Hazardous voltages that may cause death or injury are exposed during the following test. Use great care when working with AC power line voltage.

To perform the earth ground test procedure

1.Obtain a suitable voltmeter, and set it for a possible reading of up to 250VAC.

2.Connect the meter probes between the two main AC voltage terminals (white and black wires) on the wall outlet. The reading obtained should be between 100~125VAC.

3.Move one of the meter probes to the third terminal (green wire ground). Either the same reading or a reading of zero volts should be obtained.

4.If the reading is zero volts, leave one probe on the ground terminal and move the other probe to the second voltage terminal.

CAUTION! If a reading of zero volts is obtained on both voltage terminals (white wire to green wire, black wire to green wire), the outlet is not properly grounded. Omit Steps 5 and 6, and see following CAUTION!

5.If a reading of zero volts on one terminal, and a reading of 100~125VAC on the other terminal is obtained, remove both probes from the outlet.

6.Set the meter to the “OHMS/Rx1” scale. Place one probe on the ground terminal, and the other probe on the terminal that produced a reading of zero volts. The reading should be less than 1 ohm.

CAUTION! If the reading is more than one ohm, then the outlet is not adequately grounded. If the above tests show the outlet AC voltage is not in range or is not properly grounded, the condition should be corrected (per Article 250 of the National Electrical Code) by a qualified electrician before the system is connected.

CTX100 Installation Strata CTX100-S/

Alternate or Additional Ground

If the “third-wire” AC ground can not practically be improved or if extreme motor noise or other disturbance causes system malfunction, or if local area lightning storms exist, a separate direct ground may be warranted.

Connect an alternate earth ground from a cold water pipe or earth grounding rod directly to the screw terminal on the CTX100 power supply (see Figure 3-2).

Strata CTX I&M 06/04 3-5