GREYSTONE GFS-U Differential Pressure Switch Instruction Manual
- June 4, 2024
- Greystone
Table of Contents
GREYSTONE GFS-U Differential Pressure Switch
INTRODUCTION
The differential pressure switch housing unit contains a diaphragm, a snapacting SPDT switch, and a range adjustment knob with increments. The sample connections located on the side accept 6.35mm (0.25″) OD tubing. There are various optional pressure ranges, and 2 pickup tubes and 2 m (6.56′) of PVC tubing available. The enclosure cover guards against accidental contact with the live switch terminal screws and the setpoint adjustment knob with indication.
BEFORE INSTALLATION
The electrical equipment may only be installed, added to, changed or maintained by authorized electricians. No voltage is to be applied when you work on electrical installations.
ELECTRICAL CONNECTIONS
Use a three wired cable with an outer diameter of 5-10mm for the electrical
connection. Either tighten the screwed cable gland or insert a conduit tube
with 1/2″ thread and tighten with a torque of 2.5NM. See Figure 1.
The connections are intended for 6.3mm crimp-type-sockets. Assemble flex- and
solid wires accordingly. See Figure 2.
The switch (P) in the pressure switch is designed as a change over contact.
Pole 3 (COM) closes to pole 2 (NO) at increasing pressure and to pole 1 (NC)
at decreasing pressure. See Figure 3. Protect the feed line to pole 3
(COM), either in the control system or along the line (F), as shown in
Figure 4 as follows:
Max. 1.0 A / 250 VAC 50-60 Hz, at ohmic consumers.
Max. 0.4 A / 250 VAC 50-60 Hz, at inductive consumers.
Max. 0.1 A / 24 VDC 50-60 Hz, at the low-voltage version.
HOSE CONNECTIONS
Hoses are not to be bent or damaged during mounting. Leaking hoses and leaking hose connections cause disturbances on the device or inaccurate measurements. It is essential to remove the cap for transportation safety mounted on P2.
Inner hose diameter = 5.5mm for optimal clamping
P1 = Over pressure measurement (Bottom Port)
P2 = Vacuum measurement (Top Port)
P1 & P2 = Differential pressure measurement
SWITCHING PRESSURE ADJUSTMENT
Caution. Make absolutely sure that no voltage is applied to the electrical connections BEFORE any settings on the pressure switch are carried out.
Set the desired pressure trip point (which trips at increasing pressure) using
a flathead screw driver. The switch returns to its resting position as soon as
the pressure falls below the set switching differential. See Figure 5.
Replace the cover on the switch as illustrated in Figure 6. Do not operate
the system until the housing is closed. Check the trip and reset pressure by
slowly increasing and decreasing pressure.
MOUNTING
Important: Check the pressure switch for damages. Do not use if the switch is
damaged. Do not mount the pressure switch on uneven surfaces. Do not over
tighten the screws as it will deform the the device’s base. Mount the pressure
switch with the pressure connections pointing downwards, to drain condensation
that may occur. Mount the pressure switch horizontally with electrical
connectors pointing upward only if no condensate can form.
In this position, the switching values are approximately 20 Pa higher as
indicated. In general using two screws for mounting is sufficient, as
illustrated in Figure 7. The maximum diameter of the screw head cannot
exceed 8mm.
SAFETY & LIABILITY
The existing safety regulations, the intended use and the technical data must be strictly observed. According to these regulations, plants must be zero- potential and secured against inadvertently restart. The product can not be used for U.S. FDA-controlled application areas. For damage caused by improper use no liability is assumed.
SPECIFICATIONS
Medium / Max. Operating Pressure| Air / 10 kPa for all pressure
ranges
---|---
Temperature Range| Medium and ambient temperature: -20 to 60°C (-4 to
140°F)
Storage Temperature: -40 to 85°C (-40 to 185°F)
Pressure Connectors| P1 (+): Connection to higher pressure
P2 (-): Connection to lower pressure
Weight| With / without cover: 160g / 115g
Working Life| Over 106 mechanical switching operations
Electrical Rating .| Standard Version: Max. 1.0 A (0.4 A) / 250 VAC 50-60
Hz
Low-voltage Version: Max. 0.1 A / 24 VDC
Switching Rate: Max. 6 Cycles/min
Arrangement of Contacts| Break contact – NC
Operating contact – NO
Power supply line – COM
Protection Category| With cover: IP 54
Conformity| CE; ANSI; UL508; CSA C22.2#14
Country of Origin| Germany
DIMENSIONS
