Cleveland Controls
Division of UniControl Inc.
Series
GRFS-4000
GAS Pressure Sensing Switches
Application
Mounting (Figure 1)
Series GRFS-4000 is a compact, economical switch specifically designed for use with
gas furnaces, package burners and other
fuel-burning equipment, or any application
which requires low gas pressure or flowproving. The GRFS-4000 is suitable for
use with natural, manufactured or LP gas.
These switches are available with field adjustable set point ranges or nonadjustable
set points.
Select a mounting location which is free from
vibration. The Series GRFS-4000 must be
mounted with the diaphragm in any vertical
plane in order to maintain the specified operating set point. Do not mount with either
the gas inlet or the vent connection in the
"up" position.
General Description &
Operation
The plated housing encloses a diaphragm
and a snap-acting switch. The gas inlet is
located on the high pressure side of the
diaphragm, and the vent is located on the
low pressure side of the diaphragm. The gas
inlet and vent accept a variety of pipe-thread
connector fittings suitable for gas flow applications. Various electrical configurations
are available .
An enclosure cover guards against accidental contact with the live switch terminal
screws. The enclosure cover accepts a
½" conduit connection. For additional application and technical information, please
contact the sales office.
The standard model is surface-mounted
via ⅛ NPT male connector with 5⁄16 x ½ hex
for rigid mounting to a pipe nipple. Custom
mounting configurations are available.
Gas Sampling Connection
(Figure 2)
Refer to Figure 2 to identify the gas inlet
(G) and the vent (V). Connector V must
be vented to the combustion chamber or
another non-hazardous area. The GRFS4000 is equipped with a ⅛"-27 NPT male
connector ("G") and a ⅛"-27 NPT female
connector ("V"). For sample lines 10 feet or
shorter, ⅛" pipe is acceptable. For lines up to
20 feet, use ¼" pipe. For lines up to 60 feet,
use ½" pipe. For each right angle bend, add
4 feet to the computed sampe line length to
determine the correct pipe size.
Electrical Connections
(Figure 3)
Before pressure is applied to the diaphragm,
the switch contacts will be in the normally
Cleveland Controls
Division of UniControl Inc.
1111 Brookpark Rd
Cleveland OH 44109
Bulletin LTGRFS4000-00
Fig 1: Mount with the diaphragm in any
vertical plane as shown. Never mount with
the connectors pointing upward.
closed (NC) position. Wire control and alarm
functions as shown in Figure 3
The adjustment range of a standard Series
GRFS-4000 Adjustable Set Point Switch
is 0.18±0.05" wc to 2.0"wc or 0.18±0.05" wc
to 5.0"wc. The set point of a standard Series
GRFS-4000 Non-Adjustable Set Point
Switch is 0.18±0.05" wc with a switching
differential of 0.05±0.02" wc.
Tel: 216-398-0330
Fax: 216-398-8558
Email:saleshvac@unicontrolinc.com
Web page: http://www.clevelandcontrols.com
DOWNLOAD
full-color PDF
literature at
our website!
Figure 2
Figure 3
specifications
Series GRFS-4000
Gas Pressure Sensing
Typical Reference Dimensions in Inches (Millimeters)
Switches
Mounting Position:
Surface mount with the diaphragm
in any vertical plane. Neither the gas
nor the vent connection should point
upward.
Standard Set Point Ranges:
• 0.18 ±0.05" wc to 2.0" wc.
• 0.18 ±0.05" wc to 5.0" wc.
Field Adjustable "Operate Ranges":
• 0.23" wc to 2.0" wc.
• 0.23" wc to 5.0". wc.
Field Adjustable "Release Ranges":
• 0.13" wc to 1.9" wc.
• 0.13" wc to 4.7". wc.
Approximate Switch Differentials:
• For 2.0"wc set point range:
progressive, increasing from 0.05±0.02"
wc at minimum set point to approximately 0.1" wc at maximum set point.
• For 5.0"wc set point range:
progressive, increasing from 0.05±0.02"
wc at minimum set point to approximately 0.3" wc at maximum set point.
Measured Media:
Air or natural, manufactured, LP, or
other gas that will not degrade nitrile.
Maximum Pressure:
½ psi (0.03 bar).
Operating Temperature Range:
0 to 190F(–18.0 to 882C).
Life:
100,000 cycles minimum at ½ psi
maximum pressure each cycle and at
maximum rated electrical load.
Electrical Rating:
300 VA pilot duty at 115 to 277 VAC;
15 amp noninductive to 277 VAC,
60 Hz.
Contact Arrangement:
• SPST-NO.
• SPST-NC.
• SPDT.
Electrical Connections:
• Screw terminals with cup washers.
Sample Line Connectors:
• Externally threaded 7⁄16" -24 UNS 2A
or 7⁄16" -20 UNF 2A thread with nuts and
self-aligning ferrules.
• ⅛" - 27 NPT male and female connectors.
• ¼" - 18 female thread in combination
with ⅛" - 27 NPT female connectors
Approvals: UL & CUL. CSA pending.
Shipping Weight: < 1 lb.