relays

[George JervisParticipant @georgejervis86082]

looking for a relay

[George JervisParticipant @georgejervis86082]

Hi everyone

I've been given a old electric bike, the battery pack didn't work but after carefully looking around I found the relay had a loose connecter, the relay clicked on and off when I wiggled one of the 4 wires, I've done some research on the web, but haven't been able to find a replacement, any help would be greatly appreciated please,

The relay is hls-t90 (15f) 30a 240vac 36vdc

I can only find ones for 30vdc? Their are 5 pins but only 4 being used

Many thanks

[Dave HalfordParticipant @davehalford22513]

Try a higher voltage relay Po 3000 type relays (normally 50v) would work just fine at 24v

[Ex contributorParticipant @mgnbuk]

What voltage is the relay swicthing and where in the circuit is it ?

A quick google brought up versions of HLS-T90 – a single pole power relay, so your 5 contacts would be 3 x contact (common, NO & NC) and 2 coil (you don't mention the coil voltage), but the listings I found had contacts rated 28V DC.

Nigel B.

[George JervisParticipant @georgejervis86082]

I Have added some pictures to my album if that is any help the wire came out of where it was

[SillyOldDufferModerator @sillyoldduffer]

What voltage is the battery?

30a 240vac 36vdc refers to the current carrying capacity of the contacts. A hls-t90 (15f) 30a 240vac 36vdc relay can safely switch 30 Amps at up to 240Vac or 30A at up to 36Vdc. (There's probably an additional 20% safety factor.)

If the battery is less than 30V, a 30Vdc 30A relay will be fine. If the battery is 36v, a 30V relay might arc until the contacts burn out, more likely it will work OK except that the contacts wear out sooner rather than later. You could risk it.

Arcs strike whenever a switch opens and the contacts are damaged if the arc persists for too long. The gap an arc can bridge is proportional to the voltage. However AC arcs tend to self-extinguish because a 50Hz voltage drops to zero every 20 milliseconds. DC arcs persist until the gap between opening contacts becomes too big for the voltage to bridge. Even though DC switches are often spring loaded to open with a rapid snap action, the voltage has to be kept down when breaking DC.

Dave

[George JervisParticipant @georgejervis86082]

The batteries are 3 x 12 volt 14amp l think in series

[Ex contributorParticipant @mgnbuk]

Manufacturer page for relay.

I wonder if the "36V" refers to the coil voltage if there are 3 x 12V batteries in series ? The illustrations in the link above show that the current versions of those relays have the coil voltage moulded in the case at about the place where the 36V is printed on yours. They don't list a 36V coil as standards, though, so that may be a special ? Can you measure the voltage on the two thinner wires (on the right on your first picture) when the relay is energised to check ?

I can't say I am suprised that a pin has come loose / pulled out of the relay in that installation – that relay is intended for PCB mounting, not dangling on cables. If the coil voltage can be confimed, then it should be possible to find a more suitable relay with eiither Faston or screw terminals – something like this, maybe.

Nigel B.

[George JervisParticipant @georgejervis86082]

Hi, I've measured the voltage of the thinner wires which were 36 volts, they lead to a circuit board which measures the charge left in the battery's, I'm looking for a suitable replacement if anyone could point me in the right direction for one , would be appreciated

Many thanks

I've put some more pictures in my album

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