Hi everyone, I'm new here and looking to solve a problem I have with burnt out contacts on my boat.
The problem is with a 24 volt fresh water pump that was continuously burning out pressure switches. I partially solved the problem by bypassing the pump's internal pressure switch and using a simple external one attached to a 30/40 amp relay that has a diode across it. The diode has protected the simple micro-switch that operates the relay, but the relay's contacts fail with monotonous regularity, maybe lasting 6-8 weeks with daily use.
I've decided to get proper water pressure regulation by installing a mains operated Square D switch. This will ensure a usable pressure range of 20 to 40 PSI. However, this switch also has contacts and I want to protect them with an MOV. I have found that Littelfuse have a V20E25P that will do the job nicely, but their postage costs are ridiculous! I'm having problems though in finding a similar spec MOV. Can anyone suggest a more readily available alternative. Spec below.
Manufacturer: Littelfuse
Product Category: Varistors
RoHS: RoHS Compliant Details
Brand: Littelfuse
Product: MOV
Voltage Rating DC: 31 V
Voltage Rating AC: 25 V
Clamping Voltage: 77 V
Peak Surge Current: 8000 A
Surge Energy Rating: 120 J
Capacitance: 12000 pF
Operating Temperature Range: - 40 C to + 85 C
Packaging: Bulk
Case Diameter: 23 mm
Case Width: 5 mm
Current Rating: 1 mA
Dimensions: 23 mm Dia. x 5 mm W
Lead Spacing: 8.5 mm
Mounting: Radial
Series: LV UltraMOV
Factory Pack Quantity: 500
Varistor Voltage: 39 V
Littelfuse part# V20E25P
Many thanks for any advice. Stu
The problem is with a 24 volt fresh water pump that was continuously burning out pressure switches. I partially solved the problem by bypassing the pump's internal pressure switch and using a simple external one attached to a 30/40 amp relay that has a diode across it. The diode has protected the simple micro-switch that operates the relay, but the relay's contacts fail with monotonous regularity, maybe lasting 6-8 weeks with daily use.
I've decided to get proper water pressure regulation by installing a mains operated Square D switch. This will ensure a usable pressure range of 20 to 40 PSI. However, this switch also has contacts and I want to protect them with an MOV. I have found that Littelfuse have a V20E25P that will do the job nicely, but their postage costs are ridiculous! I'm having problems though in finding a similar spec MOV. Can anyone suggest a more readily available alternative. Spec below.
Manufacturer: Littelfuse
Product Category: Varistors
RoHS: RoHS Compliant Details
Brand: Littelfuse
Product: MOV
Voltage Rating DC: 31 V
Voltage Rating AC: 25 V
Clamping Voltage: 77 V
Peak Surge Current: 8000 A
Surge Energy Rating: 120 J
Capacitance: 12000 pF
Operating Temperature Range: - 40 C to + 85 C
Packaging: Bulk
Case Diameter: 23 mm
Case Width: 5 mm
Current Rating: 1 mA
Dimensions: 23 mm Dia. x 5 mm W
Lead Spacing: 8.5 mm
Mounting: Radial
Series: LV UltraMOV
Factory Pack Quantity: 500
Varistor Voltage: 39 V
Littelfuse part# V20E25P
Many thanks for any advice. Stu