Macurco GBC-2-24 User manual

IMPORTANT: Keep these user instructions for reference.
Macurco™ GBC
Gas Boiler Controller
Installation & Operation Manual

Macurco GBC Manual
REV – 1.2 [34-2900-0690-7] 2 |Page
Table of Contents
1 General Safety Information...................................................................................................................................... 3
1.1 List of warnings................................................................................................................................................. 3
2 Use Instructions and Limitations .............................................................................................................................. 3
2.1 Use For.............................................................................................................................................................. 3
2.2 Models Options ................................................................................................................................................ 4
2.3 Features............................................................................................................................................................ 4
2.4 Specifications.................................................................................................................................................... 4
3 Installation Instructions............................................................................................................................................ 5
3.1 Location & Mounting........................................................................................................................................ 5
3.2 General Wiring Information ............................................................................................................................. 8
3.2.1 Connecting the wires to terminals: .......................................................................................................... 8
3.2.2 Terminal Connection ................................................................................................................................ 9
4 Operations .............................................................................................................................................................. 14
4.1 Power up......................................................................................................................................................... 14
4.2 GBC Configuration .......................................................................................................................................... 14
4.2.1 GBC Buzzer and Relay Settings ............................................................................................................... 14
4.3 Programming on detectors to work with the GBC ......................................................................................... 17
4.3.1 Power-Up Test Setting – “PUt”............................................................................................................... 17
4.3.2 Alarm Relay Configuration – “Arc” ......................................................................................................... 17
4.3.3 Fan Relay Setting – “FrS” ........................................................................................................................ 17
4.3.4 Fan Relay Delay Setting – “Frd”.............................................................................................................. 18
4.3.5 Fan Relay Latching Setting – “FrL”.......................................................................................................... 18
5 Appendix A – Table of Figures ................................................................................................................................ 19
6 Macurco Gas Detection Product limited warranty................................................................................................. 20
Technical Support Contact Information...................................................................................................................... 20
General Contact Information ...................................................................................................................................... 20

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1General Safety Information
1.1 List of warnings
WARNING
Each person using this equipment must read and understand the information in this User manual
before use. Use of this equipment by untrained or unqualified persons or use that is not in accordance
with this user manual, may adversely affect product performance.
GBC may not function effectively below 32 °F (0 °C) or above 125 °F (51 °C). Using the equipment
outside of this temperature range may adversely affect product.
Immediately exit any environment that causes an alarm condition on the sensor.
Do not disassemble unit or attempt to repair or modify any component of this instrument. This
instrument contains no user serviceable parts, and substitution of components may adversely affect
product performance and void product warranty.
High voltage terminals (120/240 VAC) are located within this detector, presenting a hazard to service
technicians. Only qualified technicians should open the detector case and service the internal circuits.
Ensure power is de-energized from the detector relays prior to servicing the unit. Failure to do so may
result in electrical shock.
2Use Instructions and Limitations
The Gas Boiler Controller used in conjunction with Macurco Gas detectors is used to shut down boilers in the
presence of gas. Using a single detector or up to four gas detectors the controller can control up to eight dry contact
outputs. These outputs are designed to shut down the boiler system upon the detection of carbon monoxide and/or
combustible gases such as natural gas or propane. In the event of a gas alarm the GBC will engage the relay to turn
off the necessary appliance.If the detectors are programmed in latching mode, the GBC will remain in alarm until
the reset button has been pressed. If gas is still present above the Fan Relay Setting value, the GBC will go into
alarm and latch again. The Gas Boiler Controller has a green power light, a red alarm light, a boiler reset button, and
an audible buzzer.
WARNING
Each person using this equipment must read and understand the information in this User manual
before use. Use of this equipment by untrained or unqualified persons or use that is not in accordance
with this user manual, may adversely affect product performance.
2.1 Use For
The Gas Boiler Controller (GBC) provides automated safety boiler shut down when there is detection of carbon
monoxide and/or combustible gasses detected. The GBC provides up to eight dry contact outputs that are designed
to shut down boiler systems.
WARNING
High voltage terminals (120/240 VAC) are located within this detector, presenting a hazard to service
technicians. Only qualified technicians should open the detector case and service the internal circuits.
Ensure power is de-energized from the detector relays prior to servicing the unit. Failure to do so may
result in electrical shock.

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2.2 Models Options
Model Number
Number of Relays
Input Voltage
GBC-2-24
2 Relays
24 Volts AC or DC
GBC-4-24
4 Relays
24 Volts AC or DC
GBC-6-24
6 Relays
24 Volts AC or DC
GBC-8-24
8 Relays
24 Volts AC or DC
GBC-2-120
2 Relays
120 Volts AC
GBC-4-120
4 Relays
120 Volts AC
GBC-6-120
6 Relays
120 Volts AC
GBC-8-120
8 Relays
120 Volts AC
Table 2-1 – Model Options
2.3 Features
•Shutdown up to 8 boilers individually via expansion relays
•Customize up to 4 Expansion Relay Boards
•24 VDC driver for horn/strobe (250 mA)
•Audible Buzzer 90 dBA at 1ft
•Output power supports combinations of 1 to 4 detector(s) (350 mA)
2.4 Specifications
•Size: 8” x 6” x 3” (22.9 X 20.3 X 5 cm)
•Weight: 3lbs.
•Enclosure: Opaque Polycarbonate, NEMA 4X/6P (IP66/68)
•Operating Temperature: 32 °F to 125 °F (0 °C to 52 °C)
•Ambient humidity: 0% to 95% RH non-condensing
•Voltage/Current:
oGBC-X-24: 24 VAC or 24 VDC
oGBC-X-120: 120 VAC
•Relay Rating: SPDT, 120/240 VAC, 10 A Max (resistive)
•Status Indicators (LED): Power, Alarm
•Current at 24V
oSensor Connections: (Max 4) 3W ea., 0.125 mA ea.
oGreen & Red LED: 20 mA ea.
oBuzzer: 30 mA ea.
o4 x Expansion Relay Modules (2 relays ea.) 40 mA ea.
oHorn / Strobe Output:250 mA

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3Installation Instructions
The following instructions are intended to serve as a guideline for the use of the Macurco Gas Boiler Controller. It is
not to be considered all-inclusive, nor is it intended to replace the policy and procedures for each facility. If you have
any doubts about the applicability of the equipment to your situation, consult local authorities having jurisdiction or
call Technical Support at 844-325-3050.
3.1 Location & Mounting
The Macurco GBC enclosure has 6 mounting holes and is shipped with mounting screws. Install the mounting screws
on the four corners of the enclosure. The GBC should be mounted with sufficient space all round for access to
conduit entry holes on the top and bottom side of the unit. Mount the unit in an appropriate space to see and hear
the visual and audible notification and to easily access the reset button. The enclosure comes with one predrilled
3/4” conduit at the bottom center of enclosure (conduit fitting connector not included).
Note: If additional entry holes are required, use caution when drilling new holes in the enclosure. Protect the
internal components to prevent damage while drilling.
Figure 3-1 – Internal View

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Figure 3-2 Enclosure Dimensions

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Figure 3-3 – Mounting dimensions

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3.2 General Wiring Information
All the connectors in GBC are spring tightening and will accept wire from 14 to 24 AWG.
3.2.1 Connecting the wires to terminals:
1. Strip each wire back 1/4 in. (6.5 mm).
2. Press down the white button of the connector.
3. Fully insert the bare wire into the wire cavity of the connector.
Note: When inserting the wire, make sure that the wire insulation is not inhibiting the wire from
contacting the wire contact points inside the terminal connector.
Note: When the wire is properly stripped and inserted in the terminal connector, there should not be
any bare wire exposed.
4. Release the white button.
5. Ensure that the wire cannot be easily pulled out of the connector.

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3.2.2 Terminal Connection
Refer to Figure 3-4 - below for location of different connectors in GBC.
Figure 3-4 – GBC Board Diagram

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3.2.2.1 Main Power Connection
Warning: When making connections, make sure the power is off.
The GBC offers two power input versions. GBC-X-24: 24 VAC or VDC and GBC-X-120: 120 VAC. Always check the
input power type marked on the top of the GBC Main PCBA prior to connecting power. See Figure 3-5 as an
example.
Figure 3-5 – GBC Board Diagram
There are three terminals for Power: Power, Return, Ground. See Figure 3-5. The power connections to the GBC
should be size AWG 18 (minimum) for short runs. For longer runs follow recommended power wire gauge
guidelines. Match the polarity for power connection, for the low voltage models there is a bridge rectifier, so it is not
polarity sensitive.
Wire Gauge
Maximum Run Length
(feet)
(meters)
18
500
152
16
800
244
14
1250
381
Table 3-1 Recommended Wire Gauge
Note: Only connect the GBC to Class 2 power supply.
Note: It is recommended to use an independent transformer for powering the unit(s) due to possible interferences
from other devices on the same power supply.
3.2.2.2 Sensor Connections
There are two sensor connections on the GBC. These connections provide power to the respective units and
monitor the normally close circuit that controls the GBC. The GBC can support up to four Macurco 6-Series gas
detectors (350 mA max) in any combination. The sensors must be wired in series for the normally closed circuit to
operate correctly. See Figure 3-6 and Figure 3-7.
Note: If not using Sensor Connection 2 with a gas detector a jumper wire or zero-ohm resistor is needed between
alarm and 24 V. A zero-ohm resistor is factory populated in the Sensor Connection 2; a jumper wire can be used as
in place of the zero-ohm resistor.See Figure 3-6.
X