Danfoss Pressure Switch Installation Guide
Types KP 34, KP 35, KP 36 and KP 37
Product Overview
This document provides installation instructions for Danfoss pressure switches, models KP 34, KP 35, KP 36, and KP 37. These switches are designed for pressure control applications.
Specifications
Temperature Limits:
- t₁ minimum: -40 °F
- t₁ maximum: 149 °F
- t₂ minimum: -40 °F
- t₂ maximum: 212 °F
Maximum Test Pressure (Ptest max.):
- KP 34: 87 psi
- KP 35: 319 psi
- KP 36: 319 psi
- KP 37: 465 psi
Enclosure Types:
- Drip proof IP30 (EN 60529)
- Enclosure IP44 (EN 60529)
Mounting:
The mounting panel must be plane to avoid damage to the switch. Mounting screw sizes include 8-32 UNC (M4) and a maximum of 1/8in (3mm) for specific connections.
Diagram Description: Illustrations show the front and side views of the Danfoss pressure switches, including dimensions and connection port details (1/4in.-18NPT). Another diagram shows the switch installed on a pipe with temperature limits and pressure connection. Mounting options for IP30 and IP44 enclosures are also depicted.
Installation and Safety Precautions
⚠️ CAUTION: Disconnect power supply before making wiring connections or performing service to avoid possible electrical shock or damage to equipment. Never touch live parts with fingers or tools.
No maintenance is required for the switches after final installation.
Diagram Description: A diagram illustrates the internal mechanism of the pressure switch, highlighting manual reset and test functions, and differential adjustment. Another diagram shows the wiring terminal block connections.
Note on Setting: The scale in KP units is indicative only. For accurate setting or when using according to FM approval, use an additional pressure gauge to set the unit.
Electrical Specifications and Wiring
Contact Systems:
- Contact system with standard AG contacts: Single pole changeover switch (SPDT).
- Contact system with gold contacts: Single pole changeover switch (SPDT) for low current applications (1...30 mA, 5...30 V DC).
Contact Load Ratings (Standard AG Contacts):
- Alternating current: AC-1: 16 A, 400 V; AC-3: 16 A, 400 V; AC-15: 10 A, 400 V
- Direct current: DC-13: 12 W, 220 V
Contact Load Ratings (Gold Contacts):
- Alternating current: AC-1: 10 A, 400 V; AC-3: 6 A, 400 V; AC-15: 4 A, 400 V (when Au surface is burned away)
- Direct current: DC-13: 12 W, 220 V
Wiring Guidelines:
- Use copper wire only.
- Tightening torque: 20 lb. in.
Diagram Description: Schematic diagrams show the single pole changeover switch (SPDT) configurations for both standard and gold contact systems, including line connections.
UL or FM Regulations Compliance
When used according to UL or FM regulations, the switches are recognized as a Listed refrigeration controller 61B5. The following table details voltage and current ratings:
| Voltage | FL A | LR A | Resist. A | Pilot Duty | |
|---|---|---|---|---|---|
| AC | DC | ||||
| 240 | 8 | 48 | 8A | 3A | |
| 120 | 16 | 96 | 16A | ||
| 240 | 12W |
