Soldering wires to GIGAVAC high voltage relays should be easy. The ceramic on GIGAVAC HV relays is brazed at over 800°C in a hydrogen atmosphere so no damage should occur. However, good soldering techniques should be used and heat, flux and solder should be kept to a minimum (See Fig. 1).
Fig 1, Soldering to diaphragm style relays
When soldering a wire to solder pots on GIGAVAC models such as GH1, GH3, GH5, G2, G8, G15, G18 and G60 series relays, first pre-tin the wire (See Fig. 2).
Fig 2, Pre-tin the wire for solder pot type relays
The solder pot is already tinned therefore; it does not require a large amount of solder to make a good connection. Insert the wire into the solder pot, but not all the way. The hole in the top of the solder pot is not to be used to connect a wire, but to allow heat to escape when soldering. Apply heat but use minimal amount of solder (See Fig. 3).
Fig 3, Soldering to solder pot style relays
NEVER fill the solder pot entirely with solder. If too much solder is used, it can cause a crack in the ceramic to metal seal due to different coefficients of expansion between the solder and the ceramic body. Outside atmosphere will enter and the relay will lose dielectric and high voltage isolation between contacts. This can occur immediately or over time when a load is applied to the relay.
Please wipe off all flux after soldering. Flux left on the outside of the relay can lead to loss of high voltage isolation on the outside of the relay. Do not use flux that contains any acid as this can damage the ceramic surface of the relay.