19 Service & Guarantee
20 Other products
All 4QD’s products carry the normal 12 month
guarantee against faults of original manufacture.
Outside the guarantee period, or when the fault is not
due to faulty manufacture, we can normally repair
the controller, subject to it not being of excessive age
(about 5 years)
This offer does not apply if the controller has been
modified in any way or if the controller is returned
attached to any customer’s metalwork or wiring:
such alterations/additions mean the controller won’t
fit 4QD’s test jigs and an extra charge will be made
for handling and postage, even when the controller is
covered by the guarantee.
It also saves postage (both ways) if the controller is
returned without the base plate attached.
21 More information
See us via the Internet: http://www.4QD.co.uk Email to: [email protected]
“We're in Control”
“We're in Control”
Office
30 Reach Road
Burwell
Cambridgeshire, CB5 0AH
Fax: 01638 744 080
Stores
Unit 6A
Heath Road Industrial Estate
Burwell
Cambridgeshire, CB5 0AP
4QD
I
DC wire size
Some problems are caused by the use of the wrong
wire size or type in the IDC connectors. Wire that is
too thin may make poor contact. If it is too
thick(16/0.2) it may cause shorts. Single stand wire
can break.
MOSFETs
MOSFETs do fail occasionally, but in practise
failures are very rare. They are doing an enormous
amount of work and sometimes one simply gives up:
commonly the drive MOSFETs cause their drive
resistors to burn up - a sure sign the MOSFET has
failed.
Relay drop-out
A flat battery or wiring which is too thin can cause
excessive voltage drop. If the supply voltage gets to
low then, on the 24v controllers, the battery
discharge protection operates and reduces controller
performance.
On the 12v controllers, discharge protection is not
fitted as standard - so the internal 9v rail can drop. If
it does, the relay will drop out, switching off the
controller. The controller will work happily down to
10.5v (the minimum you should discharge a battery).
Sticky relays.
The power relays are switched by the controller at
low current so are very reliable. However a wiring
error can cause an arc at the contacts which are
delicately balanced against the spring to maximise
contact pressure. So a small arc can, on occasion,
cause a relay to stick. If a relay does not click when
expected, it is worth tapping it with a screwdriver
handle, to see if it is sticking.
4QD manufacture a full range of controllers: from
our Eagle and 1QD series through to our high current
4QD series (up to 300 amps, 48v) as well as a range
of extras such as LED voltmeters for 12v and 24v,
joystick interfaces and a timer for ‘stand-off’
operation in golf caddies. We also manufacture
controllers for golf caddies, golf buggies, kiddie cars,
wheelbarrows, conveyors and other battery motor
uses.
A manual such as this cannot cover all the points
everyone may need to know. If you require more
information, the best source is 4QD's Internet site,
where there is a wealth of 4QD technical
information on motor control.
