Models 375-31H Area Monitor with Neutron Detector
Section 5
Ludlum Measurements, Inc.
Page 5-1
January 2021
Common Options and
Modifications
Relay Options
Internal Circuit-Board-Mounted Relays
A 9-pin connector with male pins provides connection to three fail-safe
form C relays, activiated by the LOW ALARM (alert), HIGH ALARM, and
instrument FAIL. These contacts are potential-free (non-powered), but can
handle 125 Vac at 0.3 A or 30 Vdc at 1 A.
For additional flexibility, additional relay options are available at extra cost:
Form C Relay (3 pin connector added) PN4558-036
:
This option allows the user to access the fail-safe form C contacts
(normally open, normally closed, and common), which activate upon
HIGH ALARM
. This is achieved by using an additional 3-pin connector
with male pins, located at the bottom of the instrument, wired in
parallel with the 9 pin D male pin connector. These contacts are
potential-free (non-powered), but can handle 125 Vac at 0.3 A or 30
Vdc at 1 A.
RL1 Relay
The added 3-pin connector has the following connections
(shown energized):
Pin 1- normally open (NO) (ORG)
Pin 2- common (BRN)
Pin 3- normally closed (NC) (RED)
Section
5
