EMERSON PS4-A Series Pressure Controls Instruction Manual

: June 14, 2024
: Emerson

EMERSON PS4-A Series Pressure Controls

EMERSON PS4-A Series Pressure Controls

General information :

For application in refrigeration systems and heat pumps according to EN 378.
A professional and appropriate storage and allocation of the devices is mandatory.

The device has a potential ignition source and has not been qualified according to ATEX standards. Installation only in “non-explosive location”.

Safety instructions

Read operating instructions thoroughly. Failure to comply can result in device failure, system damage or personal injury.
This product is intended for use by qualified personnel having the appropriate knowledge and skills like trained according to EN 13313 or a specific training for flammable refrigerants.
Flammable refrigerants require special handling and care due to its flammability. Sufficient ventilation is required during service of the system.
Contact with rapidly expanding gases can cause frostbite and eye damage. Proper protective equipment (gloves, eye protection, etc.) must be used.
Ensure that the system is correctly labelled with applied refrigerant type and a warning for explosion risk.
In a severely contaminated system, avoid breathing acid vapours and avoid contact with skin from contaminated refrigerant / lubricants. Failure to do so could result in injury.
Before opening any system make sure pressure in system is brought to and remains at atmospheric pressure.
Do not release any refrigerant into the atmosphere!
Do not exceed the specified maximum ratings for pressure, temperature, voltage and current.
Ensure that the system piping is grounded.
Before installation or service disconnect all voltages from system and device.
Observe and avoid mechanical damage of housing in order to maintain protection class.
Do not use any other fluid media without prior approval of EMERSON. Use of fluids not listed could result in change of hazard category of product and consequently change of conformity assessment requirement for product in accordance with European Pressure Equipment Directive 2014/68/EU.
Ensure that design, installation and operation comply with European and national standards/regulations.
Do not operate system before all cable connections are completed.
For flammable refrigerants only use valves and accessories approved for it!

Setting :

PS4 Pressure switches are factory preset to a specific value (see label).

Function / Type of switch : (Fig. 1,2)

Fig. 1:
Pressostat – automatic reset (NC/NO)
Function / Type of switch

Fig. 2:
High pressure cut-out (manual reset)

PS4 with automatic reset:
- PS4 Pressure switches are equipped with snap action contacts opening or closing on falling or rising pressure.
  Depending on model they are equipped with single pole single through (SPST).
PS4 with manual reset (HP only):
- Reaching the preset switching point contacts open or close and latches. After the pressure drops by appr.
  4-8 bar depending on pressure setting (high pressure switch only) the switch can be reset by pushing the reset button.

Installation :

PS4 Pressure switches should not be exposed to pulsations. Use a pulsation damper or a capillary tube connection (min.1m) when pulsations can be expected.

Mounting location : any

Pressure Connection:

Threaded connection:

Use pulsation damper and high temperature diaphragm for direct compressor mounted high pressure applications.
Do not apply torsional force to switch housing assembly during assembly

(1) = Copper gasket

Brazing Connection:

Perform the brazing as per EN 14324.
Before and after brazing clean tubing and brazing joints.
Do not exceed the max. body temperature of 70 °C!

Brazing Connection

Pressure Test :

After completion of installation, a pressure test must be carried out as follows:

according to EN 378 for systems which must comply with European pressure equipment directive 2014/68/EU.
to maximum working pressure of system for other applications.

Tightness Test :

Conduct a tightness test according to EN 378-2 with appropriate equipment and method to identify leakages from joints and products. The allowable leakage rate must be according system manufacturer’s specification.

WARNING:

Failure to pressure test or tightness test as described could result in loss of refrigerant, damage to property and/or personal injury.
The tests must be conducted by skilled personnel with due respect regarding the danger related to pressure.

Electrical connection :

Comply with local electrical regulations when wiring PS4. To maintain protection class, proper installation is mandatory.
Ensure that the cables are mounted without tension; always leave the cable a bit loose.
Ensure that cables are not mounted near sharp edges.
Do not bend or mechanically stress the cable outlet, maintain a clearance of 20 mm to neighboring parts.

Operation :

Perform a functional test of electrical circuit before charging the system with refrigerant.

Service / Maintenance :

Disconnect electrical power before service.
Defective PS4 must be replaced, they cannot be repaired.
Disconnection of electrical plug (QC version) from device only when the power is switched off.
Before any debasing ensure that the flammable refrigerant is pumped out of the system and the room around the system is well vented so no refrigerant left.
According to EN 378-4 during each periodic maintenance, tightness tests shall be carried out at the relevant part of the refrigerating system. This shall apply where appropriate following any repair.
In case of repair work or replacing the control always use new gasket Fig 3 (1).

Technical Data :

Protection class
(IEC 529/ DIN 40050)| IP67
IP00 (Terminal connection)
---|---
Temperatures
Ambient (housing)/ Storage/ transport
Medium| -40…+65 °C
-40…+135 °C
Vibration resistance| 4 g (10…250 Hz)
Fluid Group| I & II
Hazard Category (PED 2014/68/EU)| PS4-W…/PS4-B…:
IV / Module B + D
Refrigerants (ASHARE)| & Mineral-. Synthetic-. POE- Lubricant
Dimensions| Fig. 5
Pressure range| Setting| P MAX / PS
---|---|---

PS4-A…/ -W…

PS4-B…/ -R…

| 13.8-27.6 bar| 41 bar
27.7 – 38 bar| 55 bar
38.1 – 50 bar| 68 bar

Electrical rating

| 230 V AC
Ind.| < 28 V DC
Ind.|

LRA

---|---|---|---

PS4-A…/ -W…

| 6 A| 2 A| 36 A
PS4-B…/ -R…| 6 A| 2 A|

15 A

For electronic applications with low electrical loads (current <100 mA) standard contacts are not suitable. The z use of gold-plated contacts is recommended.

Type

| A| W| B| R
---|---|---|---|---
Gold contact (12,/ 24 VDC)| 250 mA| –|

–

Marking

Low Voltage Directive & ENEC05

0035 Pressure Equipment Directive

No. E258370 (A2L pending)

pending

Type Code:

Function

A Pressure controls, automatic, high pressure or low pressure
W Pressure limiters, automatic type approval acc. EN 12263, 1 silver contact with molded cable, normally closed (NC) (EN 12263 & EN 378: PSL/ PSH)
R Pressure controls, external manual reset (by hand)
B Pressure limiters, external manual reset (by hand); type approval, acc. EN 12263, (EN 12263 & EN 378: PZH)

Electrical Connection

silver contact with molded cable, normally closed (NC)
silver contact with molded cable, normally open (NO)
silver contact with quick connector QC (for push-on spades), normally closed (NC)
silver contact with quick connector QC (for push-on spades),normally open (NO)
gold-plated contact with molded cable, normally closed (NC)
L silver contact with molded cable suitable for manual reset, normally closed (NC)

Dimension

Fig. 5

7/16-20 UNF

|

Braze 6 mm or 1/4“

---|---
| Dimension

PS4-A… / PS4-W… (QC)

7/16-20 UNF

|

Braze 6 mm or 1/4“

---|---
Dimension |

PS4-B… / PS4-R…

7/16-20 UNF

|

Braze 6 mm or 1/4“

---|---
| Dimension

Customer Support

Emerson Climate Technologies GmbH
Pascal Strasse 65 I 52076 Aachen I Germany
www.climate.emerson.com/en-gb
Date: 19.04.2023
OI_PS4_A1_A2L_EN_DE_FR_ES_IT_Rev06_865025.docx

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