Bacharach HFO1234ZE User manual

Infrared Gas Detector
Installation and Operation Manual
Instruction 6490-9000
September 2016
Revision 4
Product Leadership x
x
Training
x
Service
x
Reliability
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WARRANTY POLICY
BACHARACH, INC. WARRANTS THIS GAS DETECTOR TO BE FREE FROM DEFECTS
IN MATERIALS AND WORKMANSHIP FOR A PERIOD OF ONE YEAR FROM THE DATE
OF PURCHASE BY THE ORIGINAL OWNER. IF THE PRODUCT SHOULD BECOME
DEFECTIVE WITHIN THIS WARRANTY PERIOD, WE WILL REPAIR OR REPLACE IT AT
OUR DISCRETION.
THE WARRANTY STATUS MAY BE AFFECTED IF THE GAS DETECTOR HAS NOT
BEEN USED AND MAINTAINED PER THE INSTRUCTIONS IN THIS MANUAL OR HAS
BEEN ABUSED, DAMAGED, OR MODIFIED IN ANY WAY. THIS GAS DETECTOR IS
ONLY TO BE USED FOR PURPOSES STATED HEREIN. THE MANUFACTURER IS NOT
LIABLE FOR AUXILIARY INTERFACED EQUIPMENT OR CONSEQUENTIAL DAMAGE.
DUE TO ONGOING RESEARCH, DEVELOPMENT, AND PRODUCT TESTING, THE
MANUFACTURER RESERVES THE RIGHT TO CHANGE SPECIFICATIONS WITHOUT
NOTICE. THE INFORMATION CONTAINED HEREIN IS BASED ON DATA CONSIDERED
ACCURATE. HOWEVER, NO WARRANTY IS EXPRESSED OR IMPLIED REGARDING
THE ACCURACY OF THIS DATA.
ALL GOODS MUST BE SHIPPED TO THE MANUFACTURER BY PREPAID FREIGHT.
ALL RETURNED GOODS MUST BE PRE-AUTHORIZED BY OBTAINING A RETURN
MERCHANDISE AUTHORIZATION (RMA) NUMBER. CONTACT THE MANUFACTURER
FOR A NUMBER AND PROCEDURES REQUIRED FOR PRODUCT TRANSPORT.
SERVICE POLICY
BACHARACH, INC. MAINTAINS SERVICE FACILITIES AT LOCATIONS
WORLDWIDE. SOME DISTRIBUTORS / AGENTS MAY ALSO HAVE REPAIR
FACILITIES, HOWEVER, BACHARACH ASSUMES NO LIABILITY FOR SERVICE
PERFORMED BY ANYONE OTHER THAN BACHARACH PERSONNEL. REPAIRS
ARE WARRANTED FOR 90 DAYS AFTER DATE OF SHIPMENT (SENSORS,
PUMPS, FILTERS AND BATTERIES HAVE INDIVIDUAL WARRANTIES). SHOULD
YOUR GAS DETECTOR REQUIRE NON-WARRANTY REPAIR, YOU MAY
CONTACT THE DISTRIBUTOR FROM WHOM IT WAS PURCHASED OR YOU MAY
CONTACT BACHARACH DIRECTLY.
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ALWAYS INCLUDE YOUR RMA #, ADDRESS, TELEPHONE NUMBER, CONTACT
NAME, SHIPPING/BILLING INFORMATION AND A DESCRIPTION OF THE
DEFECT AS YOU PERCEIVE IT. YOU WILL BE CONTACTED WITH A COST
ESTIMATE FOR EXPECTED REPAIRS PRIOR TO THE PERFORMANCE OF ANY
SERVICE WORK. FOR LIABILITY REASONS, BACHARACH HAS A POLICY OF
PERFORMING ALL NEEDED REPAIRS TO RESTORE THE GAS DETECTOR TO
FULL OPERATING CONDITION.
PACK THE EQUIPMENT WELL (IN ITS ORIGINAL PACKING IF POSSIBLE), AS
BACHARACH CANNOT BE HELD RESPONSIBLE FOR ANY DAMAGE INCURRED
DURING SHIPPING TO OUR FACILITY.
NOTICES
COPYRIGHTS: THIS MANUAL IS SUBJECT TO COPYRIGHT PROTECTION; ALL
RIGHTS ARE RESERVED UNDER INTERNATIONAL AND DOMESTIC
COPYRIGHT LAWS. THIS MANUAL MAY NOT BE COPIED OR TRANSLATED, IN
WHOLE OR IN PART, IN ANY MANNER OR FORMAT, WITHOUT THE WRITTEN
PERMISSION OF BACHARACH, INC.
ALL SOFTWARE WHICH BACHARACH UTILIZES AND/OR DISTRIBUTES, HOLDS
A PROPRIETARY INTEREST AND IS ALSO SUBJECT TO COPYRIGHT
PROTECTION AND ALL RIGHTS ARE RESERVED. NO PARTY MAY USE OR
COPY SUCH SOFTWARE IN ANY MANNER OR FORMAT, EXCEPT TO THE
EXTENT THAT BACHARACH GRANTS THEM A LICENSE TO DO SO. IF THIS
SOFTWARE IS BEING LOADED ONTO MORE THAN ONE COMPUTER, EXTRA
SOFTWARE LICENSES MUST BE PURCHASED.
TECHNICIAN USE ONLY
THIS UNIT MUST BE INSTALLED BY A QUALIFIED TECHNICIAN WHO WILL
INSTALL THIS UNIT IN ACCORDANCE WITH THESE INSTRUCTIONS AND THE
STANDARDS IN THEIR PARTICULAR INDUSTRY/COUNTRY. OPERATORS OF
THE UNIT SHOULD BE AWARE OF THE REGULATIONS AND STANDARDS IN
THEIR INDUSTRY/COUNTRY FOR THE OPERATION OF THIS UNIT. THESE
NOTES ARE ONLY INTENDED AS A GUIDE, AND THE MANUFACTURER BEARS
NO RESPONSIBILITY FOR THE INSTALLATION OR OPERATION OF THIS UNIT.
FAILURE TO INSTALL AND OPERATE THE UNIT IN ACCORDANCE WITH THESE
INSTRUCTIONS AND WITH INDUSTRY GUIDELINES MAY CAUSE SERIOUS
INJURY INCLUDING DEATH, AND THE MANUFACTURER WILL NOT BE HELD
RESPONSIBLE IN THIS REGARD.
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Table of Contents
SECTION 1. INTRODUCTION ........................................................................9
1.1. Overview ...................................................................................................... 9
1.2. Detection Options ........................................................................................ 9
1.2.1. Broadband vs. Gas Specific ................................................................ 9
1.2.2. Broadband Gas Detection ................................................................ 10
1.2.3. Detecting Specific Gases .................................................................. 11
1.3. Remote Controller Options ........................................................................ 15
1.4. Parts List..................................................................................................... 15
1.5. Specifications ............................................................................................. 16
SECTION 2. MOUNTING THE GAS DETECTOR.............................................17
2.1. Warnings and Prerequisites ....................................................................... 17
2.2. Mounting Locations ................................................................................... 17
2.2.1. General Placement Guidelines......................................................... 17
2.2.2. Machinery Rooms ............................................................................ 18
2.2.3. Refrigerated Spaces ......................................................................... 18
2.2.4. Chillers ............................................................................................. 19
2.3. Mounting Procedure .................................................................................. 19
SECTION 3. WIRING AND CONFIGURATION............................................... 22
3.1. Overview .................................................................................................... 22
3.2. Wiring Supply Power (24VAC or 24VDC).................................................... 23
3.3. Wiring Alarm Output (Analog Signal)......................................................... 25
3.4. Wiring the Digital Alarm Output Relay....................................................... 26
3.5. Modbus Network Configuration ................................................................ 27
3.6. Conclusion.................................................................................................. 29
SECTION 4. OPERATION AND STABILIZATION............................................30
4.1. Power Up and Warmup.............................................................................. 30
4.2. Stabilization................................................................................................ 30
4.3. Perform a Manual Zero .............................................................................. 30
4.4. Alarms ........................................................................................................ 31
4.5. Gas Detector Faults.................................................................................... 31
4.5.1. Overview .......................................................................................... 31
4.5.2. Non-Critical Faults............................................................................ 31
4.5.3. Critical Faults.................................................................................... 32
SECTION 5. CONFIGURE THE GAS DETECTOR............................................. 33
5.1. User Interface Overview ............................................................................ 33
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5.2. Setting Parameters..................................................................................... 34
5.2.1. Overview .......................................................................................... 34
5.2.2. Configuration Parameters................................................................ 34
5.3. Completing Setup....................................................................................... 42
SECTION 6. FUNCTIONAL TESTS AND ADJUSTMENTS ................................43
6.1. Introduction ............................................................................................... 43
6.2. Bump Testing vs. Adjusting Detector Response......................................... 44
6.3. Bump Testing ............................................................................................. 45
6.4. Adjustment Using Calibration Gas ............................................................. 46
SECTION 7. MODBUS COMMUNICATIONS ................................................49
7.1. Introduction ............................................................................................... 49
7.2. Communications Settings .......................................................................... 49
7.3. Analog Input Registers ............................................................................... 50
7.4. Analog Output Registers ............................................................................ 51
7.5. Input Status Flags....................................................................................... 52
7.6. Output Status Flags .................................................................................... 52
SECTION 8. TROUBLESHOOTING ...............................................................53
8.1. Fault Codes................................................................................................. 53
8.2. Diagnostics Attributes (P.-18) .................................................................... 55
8.3. Resetting MGS-250 to Default Values........................................................ 56
8.4. Other Symptoms ........................................................................................ 57
SECTION 9. REPLACEMENT PARTS AND ACCESSORIES...................................58
EU DECLARATION OF CONFORMITY............................................................... 59
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List of Figures
SECTION 1. INTRODUCTION ........................................................................9
Figure 1. MGS-250 Components ......................................................................... 9
Figure 2. Broadband Gas Groups 1-3 ................................................................ 11
Figure 3. Gas Specific MGS-250 Gas Detectors ................................................. 12
Figure 4. Changing Gas Types and Accuracy ..................................................... 14
SECTION 2. MOUNTING THE GAS DETECTOR.............................................17
Figure 5. Initial Housing Separation .................................................................. 20
Figure 6. Front and Back Views of MGS-250 Base ............................................ 21
SECTION 3. WIRING AND CONFIGURATION............................................... 22
Figure 7. Terminal Blocks and Cable Glands ..................................................... 22
Figure 8. Supply Power Wiring Options ............................................................ 23
Figure 9. Maintaining Neutral Polarity.............................................................. 24
Figure 10. Analog Output Wiring ...................................................................... 25
Figure 11. Sample Relay Output Wiring............................................................ 26
Figure 12. Modbus Network Wiring.................................................................. 27
Figure 13. Setting Network Termination Resistors ........................................... 29
SECTION 5. CONFIGURE THE GAS DETECTOR............................................. 33
Figure 14. The User Interface of the MGS-250 ................................................. 33
Figure 15. Analog Output Scaling Options ........................................................ 39
SECTION 6. FUNCTIONAL TESTS AND ADJUSTMENTS ................................43
Figure 16. Using Calibration Gas ....................................................................... 46
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List of Tables
SECTION 1. INTRODUCTION ........................................................................9
Table 1: Broadband Gas Groups and Performance (P/N 6401-0500)................ 10
Table 2: Gas Specific Detector Measurement Performance.............................. 13
Table 3: Parts List ............................................................................................... 15
Table 4: Technical Specifications ....................................................................... 16
SECTION 3. WIRING AND CONFIGURATION............................................... 22
Table 5: Power Options and Terminal Block Connections ................................. 23
Table 6: Alarm Output Terminal Block Connections.......................................... 25
Table 7: Relay Output Terminal Block Connections........................................... 26
Table 8: Modbus Network Communications Connections ................................ 27
SECTION 4. OPERATION AND STABILIZATION............................................ 30
Table 9: MGS-250 Behavior during Alarm Conditions ....................................... 31
Table 10: MGS-250 Behavior during a Non-Critical Fault .................................. 32
Table 11: MGS-250 Behavior during a Critical Fault .......................................... 32
SECTION 5. CONFIGURE THE GAS DETECTOR............................................. 33
Table 12: Button Functions ................................................................................ 33
Table 13: Parameter Numbers, Names and Descriptions.................................. 34
SECTION 7. MODBUS COMMUNICATIONS ................................................49
Table 14: Analog Input Registers ....................................................................... 50
Table 15: Analog Output Registers .................................................................... 51
Table 16: Input Status Flags ............................................................................... 52
Table 17: Output Status Flags ............................................................................ 52
SECTION 8. TROUBLESHOOTING ...............................................................53
Table 18: Fault Codes......................................................................................... 54
Table 19: Diagnostic Attributes.......................................................................... 55
Table 20: Other Symptoms and Possible Causes ............................................... 57
SECTION 9. REPLACEMENT PARTS AND ACCESSORIES...................................58
Table 21: Replacement Parts and Accessories................................................... 58
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Section 1. Introduction
1.1. Overview
The MGS-250 NDIR (non-dispersive infrared) is a state-of-the-art fixed
gas detector which can detect a wide range of refrigerant gases. The
MGS-250 can be used on a stand-alone basis or integrated into controls
or a Building Management System (BMS).
The MGS-250 can be used in locations that require continuous
monitoring and to add gas detection solutions to an existing system.
Figure 1. MGS-250 Components
1.2. Detection Options
1.2.1. Broadband vs. Gas Specific
The MGS-250 NDIR refrigerant gas detectors are available in two
versions: broadband and gas specific.
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1.2.2. Broadband Gas Detection
The broadband gas detector (P/N 6401-0500) is used as a general
purpose gross leak detector and is factory tested and certified. It is
shipped from the factory with accuracy as shown in Table 1 (gas
dependent). If more accurate detection is needed, gas specific versions
are available, which are factory certified and calibrated to the target
refrigerant.
The broadband gas detector combines refrigerants into three groups
shown in Figure 2. Measurement performance is based on an average
response profile for all of the gases within the group.
NOTE: Greater accuracy may be achieved through the use of
calibration gas and the adjustment procedure detailed in
Section 6.
Table 1: Broadband Gas Groups and Performance (P/N 6401-0500)
Group # Value for Param 111Refrigerant As Shipped Accuracy
1P.-11 = 1
R123 ±35%
R134a ±25%
R404a ±35%
R407a ±25%
R407c r20%
R407f ±20%
R410a ±20%
R427a ±15%
R507 ±35%
HFO1233ZD ±35%
R448A ±40%
R449A ±40%
2 P.-11 = 2
R422a ±25%
R422d ±20%
HFO1234YF ±25%
HFO1234Ze ±25%
R452A ±25%
R513A ±35%
3 P.-11 = 3 R22 ±25%
4 P.-11 = 4 R32 ±35%
1 See Section 5 for information on Parameter 11 and other configuration instructions.
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Figure 2. Broadband Gas Groups 1-3
1.2.3. Detecting Specific Gases
Each gas-specific gas detector (PNs 6401-0501 to 6401-0520) is
shipped factory calibrated to its specific target refrigerant. Refer to
Figure 3 and Table 2.
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Figure 3. Gas Specific MGS-250 Gas Detectors
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Table 2: Gas Specific Detector Measurement Performance
Part Number Refrigerant1Accuracy
6401-0501 R22 ±5%
6401-0502 R123 ±5%
6401-0503 R134a ±5%
6401-0504 R404a ±5%
6401-0505 R407a ±3%
6401-0506 R407c ±3%
6401-0507 R407f ±3%
6401-0508 R410a ±3%
6401-0509 R422a ±5%
6401-0510 R422d ±5%
6401-0511 R427a ±3%
6401-0512 R507 ±5%
6401-0513 HFO1234YF ±5%
6401-0514 HFO1234Ze ±5%
6401-0515 HFO1233ZD ±5%
6401-0516 R32 ±5%
6401-0517 R448A ±5%
6401-0518 R449A ±5%
6401-0519 R513A ±5%
6401-0520 R452A ±5%
1 See Section 5 for information on Parameter 11 and other configuration instructions.
NOTE: Gas specific detectors can be re-calibrated in the field
to new target gases. Use optional calibration instructions in
Chapter 6 for increased accuracy when detecting a new target
gas that is different from the “as shipped” target gas. Refer to
the example in Figure 4.
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As Shipped
Part number 6401-0501 (R22) is factory calibrated to R22 and
has an as-shipped R22 response accuracy of r5% of reading.
Changed Gas Type
(Reduced Accuracy)
The gas detector may be changed to respond to any of the
other listed refrigerants (see parameter P.-11, in section 5.2). If
changed, the gas detector will have a lower accuracy for the
target refrigerant (without calibration). In this example, that
accuracy is r16% of reading.
Optional Recalibration
(For Improved Accuracy)
By applying calibration gas containing the new target
refrigerant, and via the routine described in Section 6.4, the gas
detector may then be adjusted to respond with the calibrated
accuracy of r5% of reading as shown in Table 2 for the new
target refrigerant.
Figure 4. Changing Gas Types and Accuracy
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1.3. Remote Controller Options
The MGS can connect to any controller through the standard analog
output (voltage and current; see Table 4 for options), the standard alarm
relay, or the digital Modbus RTU communications interface.
1.4. Parts List
Table 3 shows a list of components that are shipped with your order.
Table 3: Parts List
Part Number Description
Various (Depends on Model Ordered)
6401-0500 MGS-250, Broadband
6401-0501 MGS-250, R22
6401-0502 MGS-250, R123
6401-0503 MGS-250, R134a
6401-0504 MGS-250, R404a
6401-0505 MGS-250, R407a
6401-0506 MGS-250, R407c
6401-0507 MGS-250, R407f
6401-0508 MGS-250, R410a
6401-0509 MGS-250, R422a
6401-0510 MGS-250, R422d
6401-0511 MGS-250, R427a
6401-0512 MGS-250, R507
6401-0513 MGS-250, HFO1234YF
6401-0514 MGS-250, HFO1234ZE
6401-0515 MGS-250, HFO1233ZD
6401-0516 MGS-250, R32
6401-0517 MGS-250, R448A
6401-0518 MGS-250, R449A
6401-0519 MGS-250, R513A
6401-0520 MGS-250, R452A
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1.5. Specifications
Table 4: Technical Specifications
Specification Description
Power Supply 24 VDC @ 0.15 A min;
24 VAC, 5 VA min @ 50/60 Hz, 2.5 W max
Power Monitoring Green LED
Visual Alarm Red 4-digit LED display
Audible Alarm Buzzer (audible alarm), enable/disable
Fault Monitoring Fault codes presented to user
Analog Outputs 4-20 mA; 0-5 V; 0-10 V; 1-5 V; 2-10 V
Relay 1 relay rated 1 A @ 24 VAC/VDC (0.5A, 125V AC UL
rating)
Range 0-3500 ppm
Squelch1Readings below 75 ppm are squelched by default
Communication:
Modbus RTU over
RS-485
Baud rate: 9,600 or 19,200 (selectable)
Start bits: 1 Data bits: 8
Parity: None, odd, even (programmable)
Stop bits: 1 or 2, programmable
Retry time: 500 ms (min time between retries)
End of msg: Silent 3.5 characters
Alarm Delay Selectable; 0 to 15 minutes
IP Rating Not IP rated. An accessory splash shield is available
for areas requiring additional protection from wash
down.
Response Time T90 < 5 minutes
Temperature Rating -22qto 104qF (-30qto 40qC)
Humidity and
Elevation
5-90% relative humidity, non-condensing,
0-10,000 ft. altitude
Weights/Dimensions 6.3 oz, 4.0” x 5.5” x 1.5” (180 g, 102 x 140 x 37 mm)
Enclosure ABS plastic; UL flammability rating of 94V-0
Approvals CE, UL/CSA/IEC/EN 61010-1
1 When filtering is disabled (see parameter P.-19 on page 42), the unit will respond to
concentrations sub-10 ppm.
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Section 2. Mounting the Gas Detector
2.1. Warnings and Prerequisites
WARNING: Explosion hazard! Do not mount the MGS-250 in
an area that may contain flammable liquids, vapors, or
aerosols. Operation of any electrical equipment in such an
environment constitutes a safety hazard.
CAUTION: The MGS-250 contains sensitive electronic
components that can be easily damaged. Do not touch or
disturb any of these components.
NOTE: The mounting location of the monitor should allow it to
be easily accessible for visual monitoring and servicing.
NOTE: The monitor must be connected to a marked, suitably
located and easily reached switch or circuit-breaker as means
of disconnection.
NOTE: Connect monitor power and signaling terminals using
wiring that complies with local electrical codes or regulations for
the intended application.
CAUTION: Do NOT mount the MGS-250 directly to vibrating
machinery as the vibrations may degrade the gas detector’s
performance.
2.2. Mounting Locations
2.2.1. General Placement Guidelines
NOTE: The MGS-250 should be installed plumb and level
and securely fastened to a rigid mounting surface.
NOTE: When installed in areas that may be subjected to
water spray, the optional splash guard (P/N: 6900-0001)
should be used in conjunction with the MGS-250.
Gas detectors must be located within the appropriate wire lengths from
the central control unit (if used).
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2.2.2. Machinery Rooms
There is no absolute rule in determining the number of gas detectors and
their locations. However, a number of simple guidelines will help to make
a decision. Gas detectors monitor a point as opposed to an area. If the
gas leak does not reach the detector then no alarm will be triggered.
Therefore, it is extremely important to carefully select the gas detector
location. Also consider ease of access for maintenance.
The size and nature of the site will help to decide which method is the
most appropriate to use. Locations requiring the most protection in a
machinery or plant room would be around compressors, pressurized
storage vessels, refrigerant cylinders or storage rooms or pipelines. The
most common leak sources are valves, gauges, flanges, joints (brazed or
mechanical), filling or draining connections, etc.
xIn machinery rooms where there is little or no airflow, placement
options are:
oPoint Detection, where gas detectors are located as near as
possible to the most likely sources of leakage, such as the
compressor, expansion valves, mechanical joints or cable duct
trenches.
oPerimeter Detection, where gas detectors completely surround
the area or equipment.
xHalocarbon and hydrocarbon refrigerants are heavier-than-air
gases and as such the gas detectors should be located near ground
level (6 to 18 inches from the floor).
NOTE: Gas detectors should be positioned just far enough
back from any high-pressure parts to allow gas clouds to form
and be detected. Otherwise, a gas leak might pass by in a high-
speed jet and not be detected by the gas detector.
xMake sure that pits, stairwells and trenches are monitored
since they may fill with stagnant pockets of gas.
xFor racks or chillers pre-fitted with refrigerant gas detectors,
these should be mounted so as to monitor the compressors.
xDo not mount the gas detector directly to pipes or structures
that are subject to strong vibration.
2.2.3. Refrigerated Spaces
In refrigerated spaces, gas detectors should be located away from doors,
in the return airflow to the evaporators on a sidewall (below head-high is
preferred), or on the ceiling, not directly in front of an evaporator, nor in
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any direct airflow. In large rooms with multiple evaporators, gas detectors
should be mounted on the central line between 2 adjacent evaporators,
as turbulence will result in airflows mixing.
2.2.4. Chillers
In the case of small water- or air-cooled enclosed chiller units mount the
gas detector so as to monitor airflow to the extract fans. With larger
models also place a gas detector inside the enclosure under or adjacent
to the compressors.
For enclosed air-cooled chillers or the outdoor unit for
variable refrigerant volume and variable refrigerant flow (VRV/VRF)
systems, mount the gas detector so as to monitor airflow to the extract
fan. With large units also place a gas detector inside the enclosure
under or adjacent to the compressors.
2.3. Mounting Procedure
To open the housing as received use a flat blade screwdriver and
depress the top latch. While pushing the latch grasp the back edge of the
housing near the latch and pull the back away.
When mounted, the housing is simply opened by pressing the top latch
with a suitable screwdriver or other flat blade. With the top latch
depressed pull the housing apart by grasping the sides and pulling
straight out. With the housing separated the mounting base with terminal
blocks will be visible. See Figure 5.
IMPORTANT: Do not apply caulking or other material around
the gas detector base. The gas detector relies on air
exchange through the spaces between the base and the gas
detector housing. Do not obstruct the small gap around the
housing and the base with any material.
Step Mounting Procedure
1 Open the housing (see Figure 5).
2 Position the base to the pre-determined (acceptable) mounting
location. Use the gas detector base to mark the mounting
locations as needed. The hole pattern on the back plate is
sized to mount the gas detector onto various electrical junction
boxes. The other holes may be used as needed to mount the
gas detector to other structures, or onto a wall.
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Step Mounting Procedure
3 Wall Mount
Attach the MGS-250 base to
the mounting surface using
two #6 screws (provided)
through two of the mounting
holes, being careful not to
over-tighten the screws.
Refer to Figure 6 for the
locations of mounting holes on
the base.
Junction Box Mount
Attach the MGS-250 base to
the junction box (using
mounting hardware provided
with your junction box)
through the two junction box
holes. Refer to Figure 6 for
the locations of the two
junction box mounting holes
on the base.
4 Unless you are ready to wire the device (see section 3),
carefully snap the cover onto the base unit.
Figure 5. Initial Housing Separation
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