JH1700: Single Trip Alarm
JH1720: Dual Trip Alarm
Models JH1700 and JH1720 monitor an input frequency or pulse rate and provide relay contact HI/LO trip outputs. Both are fixed-range devices, with input ranges preset per your order.
A sensitivity adjustment allows threshold optimization for your application. Elevated-zero inputs are available; for example, 50-70 Hz. An internal jumper connects a pullup resistor for use with contact-closure or open-collector inputs.
The alarm trip points are adjustable anywhere within the input range. Deadbands also are fully adjustable, from 0.25% to 100% of span. A slide switch, accessible through the top of the enclosure, selects HI or LO trip operation (on dual alarms, HI/HI, HI/LO or LO/LO). Red/green LEDs indicate alarm status.
Alarm contacts are rated at 5 amps, 230Vac or 30Vdc. Model JH1700 provides one set of DPDT relay contacts; Model JH1720, two SPDT relays. AC and DC power options are available.
These alarms plug into any standard 11-pin circular ("octal") relay socket. JH Technology offers a socket suitable for DIN-rail or surface mounting (see the Accessories page). Pin connections are:
Pin 1: Power (AC or, if DC power option, DC plus).
Pin 2: No connection.
Pin 3: Power (AC or, if DC power option, DC minus).
Pin 4: Frequency input.
Pin 5: Input common.
Pin 6: Setpoint 1 relay NO contact.*
Pin 7: Setpoint 1 relay moving contact.*
Pin 8: Setpoint 1 relay NC contact.*
Pin 9: Setpoint 2 relay NO contact.*
Pin 10: Setpoint 2 relay moving contact.*
Pin 11: Setpoint 2 relay NC contact.*