Xylem McDonnell & Miller RB-24SE-S Instruction Manual

RB-24SE-B RB-24SE-S
RB-24SE-L RB-24SE-A
1 General information
1.1 General Safety
WARNING:
derstand instructions.
Save these instructions for future reference.
WARNING:
All work must be performed by qualified personnel
trained in the proper application, installation, and main‐
tenance of plumbing, steam, and electrical equipment
and/or systems in accordance with all applicable codes
and ordinances.
WARNING:
the electrical power before making electrical connec‐
tions.
WARNING:
This low water cut-off must be installed in series with all
other limit and operating controls installed on the boiler.
After installation, check for proper operation of all of the
limit and operating controls, before leaving the site.
WARNING:
We recommend that secondary (redundant) Low Water
Cut-Off controls be installed on all steam boilers with
heat input greater than 400,000 BTU/hour or opening
above 15 psi of steam pressure. At least two controls
should be connected in series with the burner control
circuit to provide safety redundancy protection should
the boiler experience a low water condition. Moreover,
at each annual outage, the low water cutoffs should be
dismantled, inspected, cleaned, and checked for proper
calibrations and performance.
Model RB-24SE-S Model RB-24SE-A Model
RB-24SE-L Model RB-24SE-B Conductance Type
Low Water Cut-Off
with Universal Wiring Harness For Residential 24 VAC Hot Water
Boilers
Before using this product read and un‐
To prevent electrical shock, turn off
INSTRUCTION MANUAL
WARNING:
California Proposition 65 warning! This product can ex‐
pose you to chemicals including Lead, which is known
to the State of California to cause cancer and birth de‐
fects or other reproductive harm. For more information
go to: www.P65Warnings.ca.gov.
NOTICE:
Failure to follow warning could cause property damage, personal injury or death
2 Product Description
2.1 Applications
Model RB-24SE-S
Model RB-24SE-A
Model RB-24SE-L
Model RB-24SE-B
Conductance Type Low Water Cut-Off with Universal Wiring Harness
For Residential 24 VAC Hot Water Boilers
Each wiring harness includes connectors which allow an RB-24SE LWCO to be
connected to most residential hot water boilers having a 24 volt burner circuit.
2.2 Operation for Models RB-24SE
The Model RB-24SE Low Water Cut-Off is specifically designed to provide burn‐
er cut-off if there is an unsafe water loss, which can result from a broken or leak‐
ing radiator or pipe, or a cracked section in the boiler.
Water/glycol mixtures up to 50% concentration may be used.
2.3 Specification
Temperature:
Storage: -40°F to 120°F (-40°C to 49°C)
Ambient: 32°F to 120°F (0°C to 4°C)
Humidity: 85% (non-condensing)
Maximum Water Pressure: 160 psi (11.2kg/cm
Maximum Water Temperature: 250 °F (121 °C)
Table 1: Electrical Ratings
Voltage Power Consumption
24 VAC
Enclosure Rating: NEMA 1 General Purpose
www.xylem.com/mcdonnellmiller
2
)
Switching Capacity
2.5 VA 2A at 2 VAC
MM-277L
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