Bacharach RDM800, HGM300 User Manual

HGM300 / RDM800

Refrigerant Monitoring System

Instruction 3015-4149

Installation & Operation Mini Manual

Rev. 6 – June 2005

SECTION 1 (Page 2) Introduction, standard accessories and mounting specifications.
SECTION 2 (Page3) Suggested location of HGM300/RDM800 and pickup points.

SECTION 3 (Page 4) Wiring HGM300/RDM800.

SECTION 4 (Page6) Basic HGM300/RDM800 system connection.

SECTION 5 (Page 11) Multiple HGM connections.

SECTION 6 (Page 13) Powering Up the Monitoring System

SECTION 7 (Page 14) Programming the HGM300 using the RDM800.

SECTION 8 (Page 16) Programming the HGM300 using PC software.

SECTION 9 (Page 18) Responding to alarms.

SECTION 10 (Page 20) Log interval and trend screens.

SECTION 11 (Page 21) Working with the fault screen.

SECTION 12 (Page 24) Working with the diagnostic screen.

SECTION 13 (Page 26) Whom to call.

REVISED 3/2/09

SECTION 1

Introduction

Welcome – This mini manual is an introduction to the installation and operation of the HGM300/RDM800
refrigerant monitoring system. For detailed installation / operation / maintenance information, please refer
to Instruction 3015-4148.

As you open the shipping carton locate the following items:

• HGM300 – Manufactured to your order specifications, that is, number of zones, type of air sample
fittings and dual 4-20ma DC option (if ordered)

• RDM800 – Remote Display Module (if ordered)

• Charcoal filter with “T” bolt bracket; line end filter assembly (Quantity dependant on number of

zones ordered – for 4 zones, 5 filters; for 8 zones, 9 filters; 12 zones, 13 filters; and for 16 zones,
17 filters. Do not use a filter on the exhaust line)

• Instruction manuals 3015-4148 and 3015-4149

• Optional items – Audio/Visual alarms, visual alarm, audio alarm, air sample tubing, etc. as

ordered.

Proper Mounting of the HGM300 and RDM800

HGM300 Mounting Specs RDM800 Mounting Specs

2

SECTION 2

HGM300 / RDM800 Refrigerant Gas Leak Monitor
Mechanical Room Placement

The HGM300 should be centrally located in the mechanical room and be readily accessible for easy
visual monitoring and servicing. Air sample tubing may be run in lengths up to 500 feet.

The fresh air purge line should draw from an area that does not contain any refrigerant gas and
cannot exceed 300 feet in length. The exhaust line should run to an outside location if possible.
The length of the exhaust line cannot exceed 300 feet.

Ideally, two to three pick up points spaced around each chiller will provide sufficient coverage. It may be
necessary to perform a “smoke” test of the mechanical room to determine the best locations. The smoke
test would provide the pattern of air currents present in the mechanical room.

Exhaust Fan

Sample Inlet
Pickup Point

Outside Hallway

Machine Room

Chiller

The RDM800 should be mounted outside of the mechanical room, or at least just inside of a door to the
room. This is the “split architecture design” for safety of the operator. The RDM800 can be located up to
4500 feet from the HGM300. The RDM800 is the man-machine interface by which you program the
HGM300, acknowledge alarms, and observe conditions inside of the mechanical room. Note that there
are two additional alarm relay contacts in the RDM800 that can be programmed to alarm with leak, spill,
evacuate, fault, or monitor on.

Aux. Horn/Strobe
Remote Alarm

Sample Inlet Pickup Points

Fresh air purge
from area away
from refrigerant
gas

RDM800
Remote Display

Module outside of
mechanical room

HGM300
Halogen

Gas
Monitor

3

SECTION 3

Switc

Switc

Wiring the HGM300

AC Power (In / Out) -- RS485 -- 4-20 mAdc

Dual 4-20 mAdc

Outputs

SIGNAL OUT

ONLY

RS485

Node Address

h

On/Off Power

h

Main 120Volt Power

(Used to supply power for audio/visual alarms)

Auxiliary Power 120Volt

Dual 4-20 mA

Interface Board

P/N 3015-31333

4

Leak, Spill, Evacuate &
Fault alarm wiring block

Wiring the RDM800

HGM300

RS485

Connector

Terminator for

Building Automation

RS485 Connector

Building

Automation

System RS485

Connector

Terminator for

HGM300 RS485

Connector

RDM800

relays

Main Power

5

SECTION 4

A

O

Basic HGM300/RDM800 Monitor System Connection

Most applications for the Bacharach HGM300/RDM800 monitor systems will consist of a single HGM300 and a
single RDM800.
The HGM300 should be mounted in the mechanical room and the RDM800 should be located in a control room, on
an outside wall of the mechanical room or at least, just inside the door to the mechanical room.

Connect power to the HGM300 using the two-lead connector on the far right bottom of the power supply PC board.
Make the ground connection to the screw post provided on the HGM300 door.
Auxiliary power to supply 120 VAC for wiring alarms is available from the second two-lead connector located to
the left of the main power connector.
Connect any alarms required to the four-relay connector marked “LEAK, SPILL and EVACUATE”. Connect the
“SYSTEM FAULT” relay if used.
The dual 4-20mAdc output connector is located on the left side of the HGM300 main PC board. This is a SIGNAL
OUT ONLY function. Both loops must be wired if this option is installed. If only one loop is used, the unused loop
must be shorted out.

Connect power to the RDM800 by removing the four screws holding the front panel to the RDM800 chassis. Turn
the front panel over and locate the two-lead connector on the far right bottom of the PC board. Make the line and
neutral connections and attach the ground to the screw post provided on the panel.

Connect any alarms to the two-relay connector located on the bottom center of the RDM800 PC board.

The RS-485 communication wiring between the HGM300 and RDM800 must be connected in the following
manner:
Locate the RS-485 connector marked “TO MONITOR” on the RDM800. This connector should be on the far-left
bottom of the RDM800 PC board. Connect one lead of a twisted shielded pair to the “B” connection point (the far
left point), note the wire color. Connect the second wire to the “A” connection point (the middle), note the wire
color. Connect the ground to the “GND” connection point.
Make the wire run to the HGM300 and connect the twisted shielded pair to the HGM300 RS-485 connector using
the same color code as used on the RDM800.
NOTE: With a basic system consisting of a single HGM300 and a single RDM800 the position of the
“Terminators” switches is not critical.

DUAL
4-20 MA DC
OUTPUT
SIGNAL OUT
ONLY

6

RS-485
CONNECTOR

LARM & FAULT

RELAYS

AUXILIARY
POWER

NODE
ADDRESS
SWITCH

MAIN
P

WER

HGM300 WIRING SCHEMATIC

OPTIONAL

DUAL LOOP

4-20 MADC

COMMON

COMMON

LOOP 1 ZONE

LOOP 2 PPM

ALARM RELAYS 5 AMP, 240 VDC

MAIN
PWR
BKR

RS485

LEAK SPILL EVACUATE SYS FAULT

B A GND

1C NO NC 2C NO NC 3C NO NC 4C NO NC

L N
AUX

PWR

L N
MAIN

PWR

GND

SPECIAL NOTE: TO ESTABLISH THE RS485 COMMUNICATION LINK WITH THE RDM800 OR WITH A BUILDING
MANAGEMENT SYSTEM, USE #18 GAGE AWG, MULTI-STRANDED, SHIELDED AND TWISTED PAIR, INSTRUMENT CABLE.
ENSURE THAT THE DRAIN WIRE IS CONNECTED TO THE GND TERMINAL AT BOTH ENDS.

7

HGM300 Relay Connector

Neutral

Alarm Alarm Alarm Fault

1 2 3 4

Strobe

Horn

Aux. Power Main Power

Jumper the ‘Neutral’ of the auxiliary power connector to the ‘Common’ on the relay block.
Connect one end of strobe or horn to the ‘NO’ of whichever level of alarm is appropriate for application.
The other end of strobe or horn is connected to a 120VAC power source, or to the ‘Line’ of the auxiliary

power connector.

Line Neutral

Line

8