Endress+Hauser Micropilot FMR50, Operating Instructions Manual

Page: 91 / 184

Micropilot FMR51, FMR52 HART Accessories
Hauser 91
15.1.5 Overvoltage protection
Accessory Description
Overvoltage protection for
2-wire-devices
OVP10 (1 channel)
OVP20 (2 channel)
A0021734
Technical data
• Resistance per channel: 2 * 0.5 Ω
max
• Threshold DC voltage: 400 to 700 V
• Threshold impulse voltage: < 800 V
• Capacitance at 1 MHz: < 1.5 pF
• Nominal arrest impulse voltage (8/20 μs): 10 kA
• Suited for wire cross-sections: 0.2 to 2.5 mm
2 (24 to 14 AWG)
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Ordering with device
The overvoltage protection module is preferably ordered with the device. See product structure, feature 610
"Accessory mounted", option NA "Overvoltage protection". Separate ordering of the module is only necessary if a
device is to retrofitted with the overvoltage protection.
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Order code for retrofitting
• For 1-channel devices (feature 020, option A)
OVP10: 71128617
• For 2-channel devices (feature 020, option B, C, E or G)
OVP20 : 71128619
Hosuing lid for retrofitting
In order to keep the necessary safety distances, the housing lid needs to be replaced if the device is retrofitted with
the overvoltage protection. Depending on the housing type, the order code of the suitable lid is as follows:
• GT18 housing: Lid 71185516
• GT19 housing: Lid 71185518
• GT20 housing: Lid 71185516
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Restrictions for retrofitting
Depending on the approval of the transmitter the usage of the OVP module may be restricted. A device may only be
retrofitted with an OVP module if the option
NA (overvoltage protection) is quoted unter Optional Specifications in
the Safety Instructions (XA) pertaining to the device.
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For details refer to SD01090F.
15.1.6 Gas-tight feedthrough
Accessory Description
Gas-tight feedthrough Chemically inert glass feedthrough; prevents migration of gases into the electronics housing.
To be ordered with the device: product structure, feature 610 "Accessory Mounted", option NC "Gas-tight feedthrough"