Models JH1000 and JH1020 DC Input Alarms monitor a DC voltage or current and provide relay contact HI/LO trip outputs. Both are fixed-range devices, with input ranges preset per your order. 

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 JH1000 provides one set of DPDT relay contacts; Model JH1020, two SPDT relays. Both models now include as standard a low-drift input amplifier for millivolt-level signals (formerly an extra-cost option). 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: Input plus. 
Pin 5: Input minus. 
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.*

• Notes: NO (normally open) and NC (normally closed) refer to the relay state when no power is applied. For Failsafe operation the NO contacts are closed under nonalarm conditions. The NC contacts close upon alarm and upon loss of power. The terms Setpoint 1 and Setpoint 2 refer to dual-trip alarms. For single-trip alarms, both sets of contacts respond to the one trip point.