What is the replacement for a Drayton Theta YBM3 Valve Body / Actuator assembly?

Issue

The Drayton Theta YBM3 Valve Body / Actuator assembly is to be replaced.

Product Line

Field Devices

Environment

  • Replacement
  • Drayton
  • Actuator
  • Valve
  • YBM3

Cause

The Drayton Theta YBM3 Valve Body / Actuator assembly is obsolete.>

Resolution

OVERVIEW

The Drayton Theta YBM3 Valve Body / Actuator assembly is obsolete, and there is no purpose built replacement.

The Valve Body was available in 1.1/4", 1.1/2" and 2" B.S.P. sizes and was normally installed as a mixing valve in variable temperature, constant volume, compensated heating circuits.

No Valve Body / Actuator assemblies are currently available in these sizes.

Details of the YB Valve Body may be viewed here.

 

VALVE BODY REPLACEMENT

To replace the YBM3 Valve Body the following is required:-

S-E Satchwell MB Valve Body of appropriate size - MB1552 (1.1/4"), MB1602 (1.1/2"), MB1652 (2")

Details of the MB Valve Body may be viewed here.

 

ACTUATOR REPLACEMENT

The YBM3 Actuator comprised a 3-wire electrical connection enabling it to be operated by a Mains Voltage changeover contact device as follows :- 

Terminal M1 – Open signal

Terminal M2 – Close signal

Terminal M3 – Common 

The YBM3 Actuator may be replaced by one or other of the following S-E Actuators :-

MD10B-230

MD20B-230 (if MD10B-230 not available)

Details of the MD10B-230 Actuator may be viewed here.

Details of the MD20B-230 Actuator may be viewed here.

N.B.

The YBM3 Actuator may also have included an additional 2-wire electrical connection associated with integral Transfer Switches wired as follows :- 

Terminal M4 – M1 made to M4 when YBM3 Fully Closed (230Vac)

Terminal M5 – M2 made to M5 when YBM3 Fully Open (230Vac)

Where external wiring is connected to YBM3 Transfer Switch Terminals M4 or M5 then an Auxiliary Switch Kit containing two S.P.C.O. Auxiliary Switches should be installed on the MD Actuator.

Auxiliary Switch Kit MD-S2 (914-1061-000)

Details of the MD-S2 Auxiliary Switch Kit may be viewed here.

Where external wiring is connected to YBL3 Terminal M4 then the MD-S2 Auxiliary Switch Kit should be wired as follows :-

Terminal S1 (Common) - connect to 230Vac power source

Terminal S2 (Normally Closed) - connect to 230Vac device previously connected to YBL3 Terminal M4

Terminal S3 (Normally Open) - no connection necessary

Where external wiring is connected to YBL3 Terminal M5 then the MD-S2 Auxiliary Switch Kit should be wired as follows :-

Terminal S4 (Common) - connect to independent 230Vac supply

Terminal S5 (Normally Closed) - no connection necessary

Terminal S6 (Normally Open) - connect to 230Vac device previously connected to YBL3 Terminal M5

 

LINKAGE KIT

A Linkage Kit will also be required in order to enable the MD Actuator to be mounted on the MB Valve Body.

Linkage Kit LMD/AR-MB (914-1071-000)

Details of the LMD/AR-MB Linkage Kit may be viewed here

In such 3-wire installations the YBM3 Valve / Actuator assembly only will need to be replaced, while any associated Controller and Sensors may be retained.