Manual

NXT 2-D/4-D Controller
Installation Guide
Page 4 of 6 P/N: 01997-001 Rev. I
2.0 Specifications
2.1 NXT-2D/-4D Dimensions
• NXT Controller PCB
- 6.50 inches high by 5.50 inches wide by 1.00 inch deep, not including wiring connectors
- 16.51 cm by 13.97 cm by 2.54 cm
• NXT Enclosure
- 13.00 inches high by 10.5 inches wide by 3.00 inches deep
- 33.02 cm by 26.67 cm by 7.62 cm
2.2 Linear Power Supply Requirements
• 10 to 14 VDC @ 2.5 A (maximum current draw for a fully loaded NXT-2D/-4D controller)
2.3 Current Requirements at 12 VDC
• 650 mA max for an NXT-4D Controller
• 570 mA max for an NXT-2D Controller
• 250 mA max for each NXT-4x4
• 120 mA max for each NXT-1R, NXT-3R, NXT-4R, or NXT-5R Reader
• 115 mA max for each NXT-6RK Reader
• 100 mA max for each NXT-RM Reader Interface Module
NOTE: Keri recommends using separate power supplies for the controller and the electronic locking device (magnetic
lock, door strike, etc.). Only linear power supplies or Keri approved switching power supplies should be used for the
controller (refer to the Recommended Peripherals document – p/n 01924-001). Use isolation relays (Keri p/n IRP-1)
between the controller and the electronic locking device to prevent spikes or surges from the locking device from affecting
the controller.
2.4 Relay Contact Rating
• 1 A @ 24 VDC
2.5 Operating Conditions
• 32°F to 150°F (0°C to 60°C) – 0% to 90% Relative Humidity, non-condensing
2.6 Battery/Memory Retention
• 5-year lithium battery backup to support controller RAM and real-time clock
2.7 Cable Options
RS-485 bus runs can daisy-chain together an NXT-4x4 and NXT-Reader on one line. The total cable run distance should
be no more than 500 feet from the NXT controller for runs with 4x4s and no more than 1,000 feet for Reader-only runs.
Refer to Table 2 on page 5 and Table 3 on page 5.
NOTE: Cable resistance causes a drop in voltage at the end of long cable runs. Ensure the appropriate power and current
for your device is available at the device at the end of the cable run. Heavier gauge cable reduces this effect.
NOTE: Keri does not recommend hot-plugging a Reader, RIM, or 4x4 into an NXT controller.

Remove power from the controller prior to connecting these devices.