The transfer switch monitors utility and generator power. When utility power fails or is unsatisfactory, the control starts the generator set and transfers the load to the generator set as soon as the generator reaches speed and voltage. When utility power is restored the transfer switch automatically transfers back to utility power, shutting down the generator and instantly resetting itself for the next power interruption. No action is required by the owner.

We recommend ZTS switches when purchasing any standby or primary power generator systems. If you require less features or a lower price point then this series, See the ZTG series, See GE Zenith, ZTG & ZTGDT, Residential, Commercial & Industrial Transfer Switches. If you require a switch that will handle large motor loads or inductive loads, See GE Zenith, ZTS Industrial Automatic Transfer Switches, Service Entrance. For Residential and commercial applications, See GE Zenith, ZTX Light Duty Residential & Commercial Transfer Switches. For ZTSCT Closed Transition, ZBTS Automatic Transition Bypass, ZBTSD Delayed Transition Bypass and ZBTSCT Closed Transition Bypass, See GE Zenith, ZTSCT, ZBTS, ZBTSD & ZBTSCT, Industrial Automatic Transfer Switches. Prices and the most common accessories are online on this website for all models.

• GE Zenith’s ZTS Series Automatic Transfer Switches are designed for emergency and standby applications.
• Standard models in stock, dropped shipped to your location. FREE SHIPPING when purchased with a generator!
• Sizes include 40 to 4,000 amps with 2, 3 or 4 pole configurations.
• Available 120/240 VAC, 120/208 VAC, 277/480 VAC and other voltages up to 600 VAC. See Factory Brochure under Additional Information.
• Switch is true double throw, mechanically interlocked and mechanically held, electrically operated utilizing a reliable, field-proven single solenoid operator.
• Switch mechanism absolutely prohibits connecting both sources together. Cannot be over-ridden.
• Available in ZTS (standard) or ZTSD (delayed transition) models. For other transition models see the link above.
• Available in Utility to Generator, Utility to Utility and Generator to Generator application configurations.
• Available in NEMA Type 1 (indoor), 3R (outdoor) enclosures and open (back-panel mounted) configurations as well as NEMA 4, 4X & 12.
• Dimensions shown on ZTS Dimensions under Additional Information.
• GE Zenith’s ZTX switches are equipped with the MX2500 control panel. This microprocessor control includes:
• Under-voltage sensing (90% pickup, 80% dropout) of Source 1 (normal).
• Voltage and frequency sensing of Source 2 (emergency), (90% voltage, 95% frequency pickup).
• Time Delay Engine Start (P) - 0-10 seconds, factory setting 3 seconds.
• Time Delay Engine Warm-up (W) - Transfer to Emergency (Source 2) - 0 -5 minutes, factory setting 1 second.
• Time Delay Utility Stabilization/Retransfer to Utility (Source 1) (T) - 0-60 minutes, factory setting 30 minutes.
• Time Delay Engine Cool Down (U) - 0-60 minutes, factory setting 5 minutes.
• Generator exerciser timer built-in. 365 day adjustable time setting. Factory set at 7 days. Exercises Source 2 with or without load.
• Switches feature contacts that are easily accessible for easy inspection and preventive maintenance.
• Rated for standby applications and intended for use only in optional (non-critical) standby systems in accordance with the National Electrical Code. NEC/NFPA 70, Article 702.
• Not intended for emergency or life-support systems.
• Qualified and listed to
UL 1008, CSA 22.2 and IEC, 480 VAC 50/60 Hz for automatic transfer equipment standards.
• For technical data, dimensions, features, remote controls, monitoring, warranty and other information. See Additional Information below.
  

  Sequence of Operation of A Transfer Switch

  When Source 1 voltage fails or drops to a predetermined point (usually 80% of nominal), if required, a circuit is closed to start the engine generator set.

  When Source 2 reaches 90% of rated voltage and 95% of rated frequency, the drive solenoid is energized through the Source 2 coil control relay, causing the main contacts to disconnect the load from Source 1 and connect it to Source 2.

  After the drive solenoid has completed its electrical stroke and is seated, the Source 2 coil control relay opens to disconnect it.

  The transfer switch is now mechanically locked in the Source 2 position.

  When Source 1 voltage is restored to a predetermined point (usually 90% of nominal), the control voltage sensing energizes.

  The Source 1 side coil relay closes, and after the drive solenoid has completed its electrical stroke and is seated, the coil control relay opens to disconnect it.

  The transfer switch is now mechanically locked in the Source 1 position.

  It then smoothly shuts the generator down after a one minute cool down period to extend generator life.

  The ZTS switch automatically performs a test to simulate utility power failure every 14 days.

  The user-friendly control panel also allows you to manually run a test at the push of a button.

  LED indicators let you know the availability of both power sources and transfer switch positions.