4
sensing.honeywell.com
MICRO SWITCH VPX Series
ISSUE F
32312068
Ui = 16V
Ii = 25 mA
Pi = 34 mW
Ci = 100 nF
Li = 100 µH
Uo ≤ Ui
Ui = 16V
Io ≤ Ii
Ii = 25 mA
Po ≤ Pi
Pi = 34 mW
Co ≥ Ci + Ccable
Ci = 100 nF
Lo ≥ Li + Lcable
Li = 100 µH
A certified associated apparatus with
zone and group approval and
with entity parameters:
VPX VALVE POSITION INDICATOR
SWITCHING AMPLIFIER
Proximity
Switch #1
Proximity
Switch #2
Switch 1 L+
Switch 1 L-
Switch 2 L+
Switch 2 L-
HAZARDOUS (CLASSIFIED) LOCATION
NON-HAZARDOUS LOCATION
Zone 0, 1, 2
Figure 3. Intrinsically Safe Zone Diagram
Table 2. Proof Test Procedure
Step Action
1
Bypass safety PLC and/or take alternative actions to avoid false trip.
2
Visually inspect the VPX Valve Position Indicator for signs of wear or damage.
3
Perform the proof test by manually operating the valve being monitored and perform a full stroke.
4
Monitor the visual indication and switch outputs and record test results as per local procedure.
5
Remove the safety PLC bypass and restore the safety system for normal operation.
MCTF Mechanical Life(Cycles) MCTF Electrical Life(Cycles)
Highest SIL
S.NO
Catalog
Value
Reference
Value
Reference
SIL Level HFT
1
SC
2
PTI
3
PT
4
Staandard Reference
1
VPX Series - Electro-
mechanical snap-
action switches loaded
at 16 A, 250 Vac
> 500,000 with
Single Sided
Confidence Limit
of 100%.
SIRA TA
16002/01
> 25,000 with
Single Sided
Confidence
Limit of 50%
SIRA TA
16001/01
SIL 3
0
SC 3
1 year
Type A
IEC
61508-2:
2010
SIRA FSP
16005/00
2
VPX Series - Electro-
mechanical snap-
action switches loaded
at 0.5 A, 250 Vdc
> 500,000 with
Single Sided
Confidence Limit
of 100%.
SIRA TA
16002/01
> 10,000 with
Single Sided
Confidence
Limit of 100%.
SIRA TA
16001/01
SIL 3
0
SC 3
1 year
Type A
IEC
61508-2:
2010
SIRA FSP
16005/00
3
VPX Series - Intrensi-
cally safe proximity
switches
> 500,000 with
Single Sided
Confidence Limit
of 100%.
SIRA TA
16004/01
> 50,000 with
Single Sided
Confidence
Limit of 100%.
SIRA TA
16003/01
SIL 3
0
SC 3
1 year
Type A
IEC
61508-2:
2010
SIRA FSP
16005/00
Notes:
1
HFT: Hardware Fault Tolerance;
2
SC: Systematic Capability;
3
PTI: Proof Test Interval;
4
PT: Product Type
INTRINSICALLY SAFE PROXIMITY SWITCHES
A VPX equipped with proximity switches is considered intrinsi-
cally safe when used with an appropriate switching amplifier,
also referred to as an associated apparatus, which complies
with EN 60947-5-6:2000 or IEC 60947-5-6:1999. The ampli-
fier contains a dc source to supply the control circuit and is
controlled by the variable internal resistance of the proximity
switch. This amplifier is placed outside of the hazardous area. A
diagram of the typical installation is shown in Figure 3.
Cable capacitance, Ccable, plus intrinsically safe equipment
capacitance, Ci, must be less than the marked capacitance, C
O
,
shown on any associated apparatus used. The same applies for
inductance (Lcable, Li and Lo, respectively). Where the cable
capacitance and inductance per foot are not known, the follow-
ing values shall be used: Ccable = 200 pF/m., Lcable = 1
μ
H/m.
The associated apparatus output current must be limited by a
resistor such that the output voltage-current plot is a straight
line drawn between open-circuit voltage and short-circuit cur-
rent. The associated apparatus must be installed in accordance
with its manufacturer’s control drawing. When required by the
manufacturer’s control drawing, the associated apparatus must
be connected to a suitable ground electrode per local instal-
lation codes, as applicable. The resistance of the ground path
must be less than 1 Ohm. Associated apparatus must not be
