R&M Materials Handling HOIST MONITORS - Manual (Page 101)

R&M Materials Handling, Inc.
4501 Gateway Boulevard
Springfield, Ohio 45502
P.: (937) 328-5100
FAX: (937) 325-5319
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R&M Materials Handling, Inc. reserves the right to alter or amend the above information without notice.
Appendix 6 - External power supply for ESD 143
General
The current of 10VDC of the Control Pro is limited to 50mA. When KAE400 (ESD142), strain-gauge
sensor and EDS143 or KAE400 (ESD142) and two strain-gauge sensor is used simultaneously the
needed current is much over 50mA. Furthermore, the current of relay card ESD143 alternates depending
on the state of the relays. That affects to the output voltage of the Control Pro and also to the accuracy of
the load measuring. In worst case the relay card starts to vibrate because of voltage alternation.
That is why external power supply is used whenever ESD143 or two strain-gauge sensors and KAE400
(ESD142) is used. After tests it has been decided that ETA Power Source WRM22FWX-U (from Perel
Oy) is started to use. Test results can be seen below.
Technical data
Type WRM22FWX-U
Input Voltage AC115-230V
Input Current 0.45A
Input Range AC85-264V(DC110-350V)
Input Frequency 50/60Hz
Output Voltage [V] 2*12VDC
Output Current [A] 0,8A; 0,5A
Operating Temperature -5 to +40ºC(unit without coer:-5 to +50ºC)
Operating Humidity
30 to 85%RH(non-condensing)
Connection
There are two separate 12 VDC outputs (V1-G1, V2-G2) at the power supply. What we need is 12 VDC
for KAE400 (ESD142) and strain gauge sensor and 24 VDC for ESD143. Therefore one 12 VDC output
(V1) is connected to the ground of the other one (G2). This way voltage between V2 and G1 will rise to
up 24 VDC.
Instead of 18 VAC, 24 VDC is connected to the ESD143. So, external AC transformer is not needed
anymore. Zeros of the ESD143 (X1:1, X1:9) is connected together. Voltage output V1 (12 VDC) replaces
the 10 VDC output of the Control Pro (:25). Zero volt (:G1) of the power supply and Control Pro (:30) is
connected together.